success response for l1 / l2 based inter-cell mobility

Abstract

Aspects of the disclosure provide a method for wireless communications by a user equipment (UE). The method generally includes receiving signaling of a plurality of candidate target physical cell identifiers (PCIs) of at least one candidate target cell that supports physical (PHY) layer or medium access control (MAC) layer mobility signaling, participating in a handover procedure to a target cell associated with a selected one or more of the candidate target PCIs based on the PHY layer or MAC layer mobility signaling, receiving a response message from the target cell indicating success of the handover procedure, and terminating activity with one or more source PCIs after receiving the response message.

Description

[0001] Priority Statement

[0002] This application claims priority to U.S. Application No. 17 / 371,696, filed July 9, 2021, and U.S. Provisional Application No. 63 / 051,321, filed July 13, 2020, the entire contents of which are expressly incorporated by reference as if fully set forth herein and for all applicable purposes. Technical Field

[0003] Various aspects of this disclosure relate to wireless communications, and more specifically, to inter-cell mobility (e.g., handover) technologies based on Layer 1 and / or Layer 2 (L1 / L2). Background Technology

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, messaging, and broadcasting. These wireless communication systems can employ multiple access technologies that enable communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include 3GPP Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, 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, to name just a few.

[0005] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the city, country, region, and even global levels. New radios (e.g., 5G NR) are examples of emerging telecommunications standards. NR is a set of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband internet access by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefixes (CP) on both the downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] However, with the continued increase in demand for mobile broadband access, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunications standards that employ these technologies.

[0007] The control resource set (CORESET) for systems such as NR and LTE systems may include one or more sets of control resources (e.g., time and frequency resources) configured to transmit the Physical Downlink Control Channel (PDCCH) within the system bandwidth. Within each CORESET, one or more search spaces (e.g., common search space (CSS), user equipment (UE) specific search space (USS), etc.) may be defined for a given UE. Summary of the Invention

[0008] The systems, methods, and apparatuses disclosed herein each have several innovative aspects, none of which are solely responsible for the desired properties.

[0009] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE). The method generally includes: receiving signaling configuring at least one candidate target physical cell identifier (PCI) for at least one candidate target cell supporting physical (PHY) layer or media access control (MAC) layer mobility signaling; participating in a handover process based on the PHY layer or MAC layer mobility signaling to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; receiving a response message from the target cell indicating the success of the handover process; and terminating activity with one or more source PCIs after receiving the response message.

[0010] Certain aspects of this disclosure can be implemented in an apparatus for wireless communication by a UE. The apparatus generally includes a memory and at least one processor coupled to the memory, the memory and the at least one processor being configured to: receive signaling of a plurality of candidate target PCIs configured to support at least one candidate target cell for PHY layer or MAC layer mobility signaling; participate in a handover process based on PHY layer or MAC layer mobility signaling to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; receive a response message from the target cell indicating the success of the handover process; and terminate activity with one or more source PCIs after receiving the response message.

[0011] Certain aspects of this disclosure can be implemented in an apparatus for wireless communication by a UE. The apparatus generally includes: units for receiving signaling of a plurality of candidate target PCIs configured to support at least one candidate target cell using PHY or MAC layer mobility signaling; units for participating in a handover process based on PHY or MAC layer mobility signaling to a target cell associated with one or more selected candidate target PCIs; units for receiving a response message from the target cell indicating the success of the handover process; and units for terminating activity with one or more source PCIs after receiving the response message.

[0012] Certain aspects of this disclosure can be implemented in a computer-readable medium having instructions stored thereon for: receiving signaling of a plurality of candidate target PCIs configured to support at least one candidate target cell for PHY or MAC layer mobility signaling; participating in a handover process based on PHY or MAC layer mobility signaling to a target cell associated with one or more selected candidate target PCIs; receiving a response message from the target cell indicating the success of the handover process; and terminating activity with one or more source PCIs after receiving the response message.

[0013] Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a network entity. The method generally includes: sending signaling to a UE configuring a plurality of candidate target PCIs of at least one candidate target cell supporting PHY or MAC layer mobility signaling; participating in a handover process based on the PHY or MAC layer mobility signaling, whereby the UE moves to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; and sending a response message via the target cell indicating the success of the handover process.

[0014] Certain aspects of this disclosure can be implemented in an apparatus for wireless communication by a network entity. The apparatus generally includes a memory and at least one processor coupled to the memory, the memory and the at least one processor being configured to: send signaling to a UE configuring a plurality of candidate target PCIs of at least one candidate target cell supporting PHY layer or MAC layer mobility signaling; participate in a handover process based on PHY layer or MAC layer mobility signaling, whereby the UE moves to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; and send a response message via the target cell indicating the success of the handover process.

[0015] Certain aspects of this disclosure can be implemented in an apparatus for wireless communication by a network entity. The apparatus generally includes: units for sending signaling to a UE configuring a plurality of candidate target PCIs of at least one candidate target cell supporting PHY or MAC layer mobility signaling; units for participating in a handover process based on PHY or MAC layer mobility signaling, whereby the UE moves to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; and units for sending a response message via the target cell indicating the success of the handover process.

[0016] Certain aspects of this disclosure can be implemented in a computer-readable medium having instructions stored thereon for: sending to the UE signaling a plurality of candidate target PCIs of at least one candidate target cell that supports PHY or MAC layer mobility signaling; participating in a handover process based on PHY or MAC layer mobility signaling, whereby the UE is transferred to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; and sending a response message via the target cell indicating the success of the handover process.

[0017] The features and technical advantages of examples according to this disclosure have been outlined quite extensively above to provide a better understanding of the specific embodiments described below. Further features and advantages will be described below. The disclosed concepts and specific examples can be readily used as the basis for modifying or designing other structures for performing the same purposes of this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein (both their organization and manner of operation) and their associated advantages will be better understood from the following description when considered in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and not as a limitation of the definitions in the claims.

[0018] While aspects and embodiments are described herein by way of example, those skilled in the art will understand that additional implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, embodiments and / or uses may be implemented via integrated chip embodiments and other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specific to a use case or application, a wide variety of applicability to the described innovations is possible. The scope of implementations can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described embodiments. For example, the transmission and reception of wireless signals necessarily involve multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovations described herein are intended to be implemented in a variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc., of various sizes, shapes, and constructions.

[0019] To achieve the foregoing and related objectives, the one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and drawings illustrate some of the illustrative features of the one or more aspects in detail. However, these features only indicate some of the various ways in which the principles of the aspects can be employed. Attached Figure Description

[0020] Details of one or more embodiments of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. However, the drawings illustrate only some typical aspects of this disclosure and should not be considered as limiting its scope. Other features, aspects, and advantages will become apparent from the specification, drawings, and claims.

[0021] Figure 1 An example wireless communication network in which some aspects of this disclosure can be implemented is shown.

[0022] Figure 2 Block diagrams illustrating example base stations (BS) and example user equipment (UE) according to some aspects of this disclosure are shown.

[0023] Figure 3AAn example of a frame format used in telecommunications systems is shown.

[0024] Figure 3B This demonstrates how different beams can be used to transmit different synchronization signal blocks (SSBs).

[0025] Figure 4 Example architectures are shown that can be used to implement various aspects of this disclosure.

[0026] Figure 5 and 6 Example scenarios are shown that demonstrate how various aspects of this disclosure can be put into practice.

[0027] Figure 7 Example operations for wireless communication by a user equipment (UE) are shown, based on some aspects of this disclosure.

[0028] Figure 8 Example operations for wireless communication by a network entity are shown, based on some aspects of this disclosure.

[0029] Figure 9 and 10 The present disclosure illustrates a communication device that may include various components configured to perform the operations of the techniques disclosed herein, according to various aspects of this disclosure.

[0030] For ease of understanding, the same reference numerals are used where possible to denote the same elements common in the figures. It is conceivable that elements disclosed in one aspect may be usefully used in other aspects without specific description. Detailed Implementation

[0031] Various aspects of this disclosure relate to wireless communications, and more specifically, to successful responses to inter-cell mobility (e.g., handover) technologies based on Layer 1 and / or Layer 2 (L1 / L2). As will be described in more detail below, certain aspects of this disclosure provide techniques for improved handover (HO) procedures based on physical layer (PHY or L1) and / or media access control (MAC or L2) layer signaling.

[0032] For example, a User Equipment (UE) participating in an HO (Ho) procedure can receive a response message (e.g., a "success message") indicating the success of the HO procedure from the target cell. Therefore, the UE can terminate activity associated with one or more source cells, thereby improving link quality with the target cell. In some cases, the UE can terminate communication with the source Physical Cell Identifier (PCI) and / or the Physical Downlink Control Channel (PDCCH) used for one of the source PCIs. The UE can also send a response to the target PCI and / or the source PCI indicating receipt of the success message. This indication can be conveyed through various means such as a Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

[0033] The following description provides examples and is not intended to limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the elements discussed without departing from the scope of this disclosure. Various processes or components may be omitted, substituted, or added as appropriate in various examples. For example, the described method may be performed in a different order than that described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement an apparatus or practice. Additionally, the scope of this disclosure is intended to cover such apparatus or methods practiced using structures, functions, or structures and functions other than or different from the aspects of this disclosure set forth herein. It should be understood that any aspect of this disclosure may be embodied by one or more elements of the claims.

[0034] Typically, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. A frequency may also be referred to as a carrier, subcarrier, frequency channel, frequency modulation, subband, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks using different RATs. In some cases, 5G NR RAT networks can be deployed.

[0035] Figure 1 An example wireless communication network 100 in which aspects of the present disclosure can be implemented is shown. For example, such as Figure 1 As shown, UE120a may include an L1 / L2 mobility module 122, which can be configured to perform (or cause UE 120a to perform). Figure 7Operation 700. Similarly, base station (BS) 110a may include L1 / L2 mobility module 112, which can be configured to perform (or cause BS 110a to perform). Figure 8 Operation 800.

[0036] NR access (e.g., 5G NR) can support a variety of wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or higher), millimeter wave (mmWave) targeting high carrier frequencies (e.g., 25 GHz or higher), massive machine-type communication (mMTC) targeting non-backward compatible MTC technologies, or mission-critical services targeting ultra-reliable low-latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTI) to meet corresponding quality of service (QoS) requirements. Furthermore, these services can coexist in the same time-domain resources (e.g., time slots or subframes) or frequency-domain resources (e.g., component carriers).

[0037] like Figure 1 As shown, the wireless communication network 100 may include several BSs 110a-z (each BS is also individually referred to herein as BS 110 or collectively as BS 110) and other network entities. BS 110 may provide communication coverage for a specific geographic area (sometimes referred to as a “cell”), which may be stationary or mobile depending on the location of the (mobile) BS 110. In some examples, BS 110 may be interconnected with each other or to one or more other BSs or network nodes (not shown) in the wireless communication network 100 using any suitable transport network via various types of backhaul interfaces (e.g., direct physical connection, wireless connection, virtual network, etc.). Figure 1 In the example shown, BS 110a, 110b, and 110c can be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x can be a pico BS for pico cell 102x. BS 110y and 110z can be femto BSs for femto cells 102y and 102z, respectively. A BS can support one or more cells. BS 110 communicates with user equipment (UEs) 120a-y (each individually referred to herein as UE 120 or collectively as UE 120) in the wireless communication network 100. UEs 120 (e.g., 120x, 120y, etc.) can be distributed throughout the wireless communication network 100, and each UE 120 can be stationary or mobile.

[0038] The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a relay, etc.) that receives transmissions of data or other information from an upstream station (e.g., BS 110a or UE 120r) and transmits such transmissions of data or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0039] Network controller 130 can be coupled to a collection of BS 110s and provide coordination and control for these BS 110s. Network controller 130 can communicate with BS 110s via backhaul. BS 110s can also communicate with each other via wireless or wired backhaul (e.g., directly or indirectly).

[0040] Figure 2 Block diagrams illustrating some aspects of this disclosure are shown.

[0041] At BS 110, transmit processor 220 can receive data from data source 212 and control information from controller / processor 240. The control information may be for Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Group Common PDCCH (GC PDCCH), etc. The data may be for Physical Downlink Shared Channel (PDSCH), etc. Processor 220 can process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols respectively. Transmit processor 220 can also generate reference symbols, such as for primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). Transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, or reference symbols where applicable, and can provide the output symbol stream to modulators (MODs) 232a-232t. Each modulator 232 can process its own output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signal from modulators 232a-232t can be transmitted via antennas 234a-234t, respectively.

[0042] At UE 120, antennas 252a-252r can receive downlink signals from BS 110 and can provide the received signals to demodulators (DEMODs) in transceivers 254a-254r respectively. Each demodulator 254 can adjust (e.g., filter, amplify, down-convert, and digitize) its respective received signal to obtain an input sample. Each demodulator can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain received symbols from all demodulators 254a-254r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 258 can process (e.g., demodulate, deinterleave, and decode) these detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information to controller / processor 280.

[0043] On the uplink, at UE 120, transmit processor 264 can receive and process data from data source 262 (e.g., for the Physical Uplink Shared Channel (PUSCH)) and control information from controller / processor 280 (e.g., for the Physical Uplink Control Channel (PUCCH)). Transmit processor 264 can also generate reference symbols for reference signals (e.g., for Sounding Reference Signals (SRS)). Symbols from transmit processor 264 can be pre-encoded by TXMIMO processor 266, where applicable, further processed by demodulators in transceivers 254a-254r (e.g., for SC-FDM, etc.), and transmitted to BS 110. At BS 110, uplink signals from UE 120 can be received by antenna 234, processed by modulator 232, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information transmitted by UE 120. The receiver processor 238 can provide the decoded data to the data sink 239 and provide the decoded control information to the controller / processor 240.

[0044] Memory 242 and 282 can store data and program code for BS 110 and UE 120, respectively. Scheduler 244 can schedule UE to perform downlink or uplink data transmission.

[0045] The controller / processor 280 or other processors and modules at UE 120 can execute or direct the execution of processes used in the techniques described herein. For example... Figure 2 As shown, the controller / processor 280 of UE 120 has an L1 / L2 mobility module 122, which can be configured to execute (or cause UE 120 to execute). Figure 7Operation 700. Similarly, BS 110a may include L1 / L2 mobility module 112, which can be configured to perform (or cause BS 110a to perform). Figure 8 Operation 800.

[0046] Figure 3A This is a schematic diagram illustrating an example of frame format 300 for NR. The transmission timeline of each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes with indices from 0 to 9, each subframe being 1 ms long. Depending on the subcarrier spacing, each subframe can include a variable number of time slots. Depending on the subcarrier spacing, each time slot can include a variable number of symbol periods (e.g., 7 or 14 symbols). An index can be assigned to the symbol period in each time slot. A micro-time slot, which can be referred to as a sub-time slot structure, refers to a transmission time interval with a duration less than that of a time slot (e.g., 2, 3, or 4 symbols).

[0047] Each symbol in a time slot can indicate the link direction used for data transmission (e.g., DL, UL, or flexible), and the link direction can be dynamically switched for each subframe. The link direction can be based on the time slot format. Each time slot can include DL / UL data as well as DL / UL control information.

[0048] In NR, a synchronization signal (SS) block is transmitted. The SS block consists of the PSS, SSS, and two-symbol PBCH. This can be done at fixed time slot locations (such as...). Figure 3A SS blocks are transmitted in symbols 0-3 (shown). PSS and SSS can be used by the UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identification. PBCH carries some basic system information, such as downlink system bandwidth, timing information within the radio frame, SS burst set periodicity, system frame number, etc. SS blocks can be organized into SS bursts to support beam scanning. Additional system information, such as Residual Minimum System Information (RMSI), System Information Block (SIB), and Other System Information (OSI), can be transmitted on the PDSCH in certain subframes. SS blocks can be transmitted up to 64 times, for example, up to 64 different beam directions for mmW. Up to sixty-four transmissions of SS blocks are called SS burst sets. SS blocks in an SS burst set are transmitted in the same frequency region, while SS blocks in different SS burst sets can be transmitted at different frequency locations.

[0049] like Figure 3BAs shown, SS blocks can be organized into SS burst sets to support beam scanning. As illustrated, different beams can be used to transmit each SSB within a burst set, which helps the UE quickly acquire both the transmit (Tx) and receive (Rx) beams (especially for mmW applications). The Physical Cell Identifier (PCI) can still be decoded from the PSS and SSS of the SSB.

[0050] A control resource set (CORESET) for systems such as NR and LTE systems may include one or more sets of control resources (e.g., time and frequency resources) configured to transmit PDCCH within the system bandwidth. Within each CORESET, one or more search spaces (e.g., common search space (CSS), UE-specific search space (USS), etc.) may be defined for a given UE. According to various aspects of this disclosure, a CORESET is a set of time-domain and frequency-domain resources defined in units of resource element groups (REGs). Each REG may include a fixed number (e.g., twelve) of frequency modulations in a symbol period (e.g., the symbol period of a time slot), where one frequency modulation in one symbol period is referred to as a resource element (RE). A fixed number of REGs may be included in a control channel element (CCE). A set of CCEs may be used to transmit a new radio PDCCH (NR-PDCCH), where different numbers of CCEs in these sets are used to transmit NR-PDCCH using different aggregation levels. Multiple CCE sets can be defined as the search space of a UE, and thus a NodeB or other base station can send an NR-PDCCH to a UE by sending an NR-PDCCH in a set of decoded candidate CCEs defined in the search space for a UE, and the UE can receive the NR-PDCCH by searching in the search space for the UE and decoding the NR-PDCCH sent by the NodeB.

[0051] Example methods for L1 / L2 mobility

[0052] Various aspects of this disclosure relate to wireless communications, and more specifically, to mobility technologies that allow for dynamic updates of the set of cells and / or beams activated to serve a user equipment (UE). L1 / L2 inter-cell mobility is implemented based on signaling to / from the UE, as will be described in more detail below.

[0053] The techniques presented in this paper can be applied to various frequency bands used in NR. For example, for the higher frequency band known as Frequency Range (FR) 4 (e.g., 52.6 GHz – 114.25 GHz), orthogonal frequency division multiplexing (OFDM) waveforms with very large subcarrier spacing (SCS) (960 kHz – 3.84 MHz) are required to combat severe phase noise. Due to the large subcarrier spacing, the slot length tends to be very short. In the lower frequency band known as FR2 (24.25 GHz to 52.6 GHz) with a 120 kHz SCS, the slot length is 125 μs, while in FR4 with 960 kHz, the slot length is 15.6 μs.

[0054] In multi-beam operations (e.g., involving FR1 and FR2 bands), more efficient uplink (UL) and / or downlink (DL) beam management can allow for increased intra-cell and inter-cell mobility (e.g., L1 and / or L2-centric mobility) and / or a greater number of Transmission Configuration Indicator (TCI) states. These states may include, for example, the use of common beams for data and control transmission and reception for both UL and DL operations, a unified TCI framework for UL and DL beam indication, and enhanced signaling mechanisms (e.g., dynamic use of control signaling) to improve latency and efficiency.

[0055] Accordingly, the techniques presented in this paper provide signaling mechanisms that can help support such enhanced features, improve latency, and enhance efficiency by making greater use of dynamic control signaling. For example, the techniques described in this paper utilize PHY or Media Access Control (MAC, Layer 2 or L2) signaling instead of higher-layer (e.g., Radio Resource Control (RRC)) signaling.

[0056] Figure 4 An example architecture for implementing various aspects of this disclosure is shown. As illustrated, the architecture includes a gNB Central Unit (gNB-CU). The gNB-CU typically serves as a logical node housing the RRC, Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) of the gNB that controls the operation of one or more gNB Distributed Units (gNB-DUs). As shown, the gNB-CU terminates its connection to the gNB-DU via an F1 interface.

[0057] gNB-DU is typically used as a logical node housing the RLC, MAC, and PHY layers of the gNB, and its operation is controlled by the gNB-CU. For example... Figure 5 and 6 As shown, one gNB-DU supports one or more cells (but each cell is supported by only one gNB-DU). The gNB-DU terminates the F1 interface connected to the gNB-CU.

[0058] Figure 5 and 6 Example scenarios are shown where aspects of this disclosure can be put into practice.

[0059] like Figure 5 As shown, in some cases, a UE can handover between (source and target) cells supported by different DUs (radio units or RUs) under the same CU. RUs typically contain only PHY layer logic. Figure 5 In this scenario, a cell can have non-coordinated (in different DUs) PHY, MAC, and RLC logic, but share common PDCP and RRC logic (within the same CU). While the L1 / L2 signaling techniques described in this paper can be used for mobility, some control aspects of the data path presentation from the PDCP to different RLCs can be addressed through coordination between DUs.

[0060] On the other hand, Figure 6 In the scenario shown, the source and target cells are supported by the same DU (and belong to the same DU). Therefore, L1 / L2 mobility may be particularly attractive in this scenario because cells can share MAC and upper layers (the same DU). In this scenario, when a handover is performed via L1 / L2 signaling, the data path of the MAC and upper layers remains the same.

[0061] As described above, the distributed RU contains only the PHY layer and can be used in a manner similar to carrier aggregation (CA) (activation / deactivation), but the cells can operate on the same carrier frequency. Therefore, aspects of this disclosure can utilize mechanisms similar to those used in CA to achieve L1 / L2 mobility (e.g., cell activation / deactivation).

[0062] As an initial step, RRC signaling can be used to configure the cell set for L1 / L2 mobility. Typically, this cell set can be designed to be large enough to cover meaningful mobility (e.g., the expected mobility of the UE in a given area and time). Mobility management can be performed by activating / deactivating cells in the set, as described below.

[0063] Depending on the configured set, a set of cells can be activated at any given time. This set of activated cells typically refers to one or more cells that are active within the configured set. If the set of activated cells includes two or more active cells, the UE can switch from one active cell to another via dynamic (e.g., PHY / MAC) signaling.

[0064] Which cells are activated for any given UE may depend on the measurements reported by the UE. The inactive configured cells (deactivated cell set) may include the (remaining) group of cells that have been deactivated (not activated) in the configured set.

[0065] Example target PCI selection

[0066] This disclosure provides apparatus, methods, processing systems, and computer-readable media for implementing L1 / L2 inter-cell mobility based on signaling to / from a user equipment (UE). In some cases, L1 / L2 signaling can be used to indicate the target physical cell identifier (PCI) selected for handover.

[0067] Some features described in this paper can facilitate uplink (UL) beam selection for UEs equipped with multiple panels. For example, UL beam selection can be facilitated by UL beam indication based on the Unified Transport Configuration Indicator (TCI) framework, enabling simultaneous transmission across multiple panels and achieving fast panel selection. Furthermore, UE-initiated or L1 event-driven beam management can reduce latency and the probability of beam failure events.

[0068] Additional enhancements for multiple transmit-receive point (TRP) deployments can target both FR1 and FR2 bands. These enhancements can improve the reliability and robustness of channels other than PDSCH (e.g., PDCCH, PUSCH, and PUCCH) using multiple-TRP and / or multi-panel operation. In some cases, these enhancements can be associated with quasi-co-location (QCL) and TCI, which enable inter-cell multiple-TRP operation and allow simultaneous multiple-TRP transmissions with multi-panel reception (assuming multi-PDSCH reception based on multi-DCI).

[0069] Furthermore, additional enhancements can support single-frequency networks (SFNs) in high-speed environments, such as high-speed train (HST) scenarios. These enhancements can include QCL assumptions for the demodulation reference signal (DMRS), such as multiple QCL assumptions for the same DMRS port and / or targeting downlink-only transmissions. In some cases, these enhancements can be achieved by using a unified TCI framework to specify the QCL or similar QCL relationship between downlink and uplink signals, including the applicable QCL types and associated requirements.

[0070] In Rel-15 and Rel-16, each serving cell can have a serving cell identifier (ID) configured by RRC and a physical cell indicator (PCI) configured by RRC. The UE can also obtain the PCI from the synchronization signal block (SSB) of the serving cell.

[0071] To enable L1 (e.g., physical layer) / L2 (e.g., media access control (MAC) layer) inter-cell mobility, the gNB may need to know whether the UE supports L1 / L2 mobility. L1 / L2-based inter-cell mobility can include various operating modes. In a first operating mode, each serving cell can have one PCI and multiple physical cell sites (e.g., remote radio head ends (RRHs)). Each RRH can use the same PCI to transmit different sets of SSB IDs. The DCI or MAC-CE can select which RRH or corresponding SSB to serve the UE based on a signal strength metric (e.g., reference received power (RSRP)) for each reported SSB ID.

[0072] In another operating mode, each serving cell can be configured with multiple PCIs. Each RRH of the serving cell can use one of the multiple PCIs configured for that serving cell and can transmit the complete set of SSB IDs configured for that cell. The DCI or MAC-CE can select which RRH(s) or corresponding PCI and / or SSB(s) to serve the UE based on a signal strength metric (e.g., Reference Signal Received Power (RSRP)) for each reported SSB ID of each reported PCI.

[0073] In another operating mode, each serving cell can be configured with a single PCI. The DCI or MAC-CE can identify one or more serving cells or their corresponding serving cell IDs to serve the UE based on a signal strength metric (e.g., RSRP) for each reported SSB ID of each reported PCI.

[0074] While the selection or use of SSBs has been mentioned above, it should be understood that other cell identification reference signals can be used to identify the serving cell to serve the UE. For example, Channel State Information (CSI) Reference Signal (CSI-RS) or Position Reference Signal (PRS) can be used to identify one or more serving cells to serve the UE.

[0075] In some embodiments, during L1 / L2 inter-cell mobility, the UE can be configured with multiple candidate cells (e.g., PCI) for L1 metric measurement and reporting. L1 metric measurement and reporting may waste power when the UE is stationary or substantially stationary. The UE may continue reporting L1 metrics while stationary, and it may take some time for the gNB to determine that the UE is stationary based on the reported L1 metrics.

[0076] Successful response for example based on L1 / L2 inter-cell mobility.

[0077] This disclosure provides apparatus, methods, processing systems, and computer-readable media for Layer 1 (L1) / Layer 2 (L2) based inter-cell mobility, relating to providing a user equipment (UE) with an indication of successful handover (e.g., a "success response") from a target cell. The UE can then terminate activity in one or more cells associated with the same or more source PCIs.

[0078] To reduce handover (HO) latency, L1 / L2-based inter-cell mobility was previously introduced (in Rel-17). In L1 / L2-based HO, each serving cell can have multiple Physical Cell Identifiers (PCIs) for a Remote Radio Header (RRH), which can be located in different physical locations. The gNB can dynamically select a subset of the same serving cell's PCIs to serve the UE via L1 / L2 signaling (e.g., DCI or MAC-CE). In another implementation, each serving cell can have a single PCI (e.g., as defined in the specification of each serving cell). The gNB can dynamically select at least one serving cell to serve the UE via L1 / L2 signaling.

[0079] Furthermore, L1 / L2 inter-cell mobility based on a random access channel (RACH) can be implemented in the above example. In this case, the UE can select one or more PCIs, and if the HO condition is met for the selected one or more PCIs, a (RACH) procedure is initiated for the selected one or more PCIs, rather than the gNB selecting one or more PCIs. For example, multiple candidate target PCIs can be pre-configured at the UE by the gNB.

[0080] The gNB can also configure the UE to measure the L1 metric for each candidate target PCI. The L1 metric may include L1 Reference Signal Received Power (RSRP) and / or L1 Signal-to-Interference-plus-Noise Ratio (L1-SINR). The gNB can also configure at least one HO condition for each candidate target PCI. For example, the HO condition can use the L1 metric as input.

[0081] Whenever the HO condition is met for a candidate target PCI, the UE can initiate a synchronous (e.g., via RACH) reconfiguration on the UL resources configured for that PCI. The completion of a RACH-based L1 / L2 HO can be indicated by an HO completion message signaled via L1 / L2 signaling. This HO completion message can be sent from the UE to the RRH and / or the cell associated with the candidate target PCI. Alternatively, the HO completion message can be received by the UE.

[0082] After the gNB or UE initiates an L1 / L2-based cell selection, the UE can begin communicating with the selected PCI(one or more) and cease monitoring the older PCI(one or more). However, it may be beneficial to confirm successful reception of handover signaling from the target cell associated with the selected PCI(one or more). For example, when making the cell selection decision, the selected PCI(one or more) may have degraded link quality due to outdated channel measurements. Therefore, communication on the selected PCI(one or more) may not proceed.

[0083] Therefore, some aspects provide a mechanism for the selected PCI(one or more) to send a success response to the UE to confirm the success of the handover signaling. Upon receiving this success response, the UE can safely terminate communication with / monitoring of the old PCI(one or more). Specifically, after initiating L1 / L2-based cell selection, the RRH / cell associated with the selected PCI(one or more) can send a success response to the UE (e.g., within a certain time window).

[0084] Figure 7 Example operation 700, which can be performed by a UE to receive a successful response in L1 / L2-based mobility, is shown according to certain aspects of this disclosure. Operation 700 can be performed, for example, by... Figure 1 The UE 120 shown in the figure is used for execution.

[0085] Operation 700 begins at 702, receiving signaling for multiple candidate target PCIs of at least one candidate target cell configured to support physical (PHY) layer or media access control (MAC) layer mobility signaling. At 704, the UE participates in a handover procedure based on PHY layer or MAC layer mobility signaling to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs. At 706, the UE receives a response message from the target cell indicating that the handover procedure was successful. In some aspects, this success response may be carried in L1 / L2 signaling (e.g., DCI or MAC-CE).

[0086] At 708, the UE terminates its activity with one or more source PCIs after receiving a response message. In some respects, terminating activity may include ceasing communication with (one or more) legacy PCIs and / or monitoring the Physical Downlink Control Channel (PDCCH) on (one or more) legacy PCIs.

[0087] Figure 8 It shows what can be considered to be related to Figure 7 Example operation 800 is complementary to operation 700. For example, operation 800 can be performed by a network entity (e.g., Figure 5Or 6 of gNB DU / CU) to execute, to send to UE (execute) Figure 7 Operation 700) provides a successful response based on L1 / L2 mobility.

[0088] Operation 800 begins at 802, sending signaling to the UE to configure multiple candidate target PCIs for at least one candidate target cell that supports PHY layer or MAC layer mobility signaling. At 804, the network entity participates in a handover procedure based on PHY layer or MAC layer mobility signaling, for the UE to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs. At 806, the network entity sends a response message via the target cell indicating the success of the handover procedure.

[0089] In some respects, upon receiving a successful response, the UE may further send an acknowledgment indicator to one or more old PCIs and / or one or more new PCIs to indicate that a successful response has been received. This acknowledgment indicator may be carried in L1 / L2 signaling (e.g., Physical RACH (PRACH), Sound Reference Signal (SRS), Uplink Control Information (UCI), MAC-CE, etc.).

[0090] As described above, in some cases, the gNB can initiate L1 / L2 mobility. In this case, the gNB can indicate the selected PCI(one or more) to the UE via L1 / L2 signaling. In some examples, after receiving this indication (e.g., PCI and / or cell selection command), the UE can begin monitoring the PDCCH on the RRH / cell associated with the selected PCI(one or more) PCI(one or more). Then, after the gNB sends the PCI / cell selection command to the UE, the selected RRH / cell can send a success response.

[0091] The success response can be carried in the downlink control information (DCI), which can be scrambled by the cell radio network temporary identifier (C-RNTI) assigned to the UE for a specific PCI. In some cases, the success response can be sent within the time window at which the gNB begins transmitting the selection command.

[0092] In some respects, after receiving a PCI / cell selection command, the UE can send an uplink (UL) signal as a cell selection request to the RRH / cell associated with the selected PCI(one or more) PCIs. This UL signal can be a PRACH preamble, SRS, Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), etc. The selected RRH / cell can then send a success response after receiving the UL signal from the UE, and this success response can be carried in a DCI, which can be scrambled by the C-RNTI assigned to the UE for that specific PCI. Similar to the above, this success response can be sent within a time window starting from the receipt of the UL signal from the UE.

[0093] As mentioned above, in some cases, a UE can initiate L1 / L2 mobility. In this case, the UE can select one or more new PCIs that meet the cell selection criteria and initiate RACH to the RRH / cell associated with the selected PCI(one or more) PCI(one or more).

[0094] In the case of RACH based on Contention-Free Random Access (CFRA), after sending the RACH preamble, the UE can begin monitoring the PDCCH on the RRH / cell associated with the selected PCI(one or more) PCIs. The selected RRH / cell can then send a success response after receiving the preamble from the UE, and this success response can be carried in a DCI, which can be scrambled by the C-RNTI assigned to the UE for that specific PCI. Similar to the above, this success response can be sent within a time window starting from the receipt of the UL signal from the UE.

[0095] For RACH based on Contention-Based Random Access (CBRA), after sending the RACH preamble, the gNB can respond with a message that schedules subsequent messages (e.g., a Random Access Response (RAR) message). The UE can also send its identifier (e.g., the C-RNTI assigned to that PCI) in any later UL message / transmission. The selected RRH / cell can send a success response after receiving the identifier from the UE, and this success response can be carried in a DCI, which can be scrambled by the C-RNTI assigned to the UE for that PCI. Similar to the above, this success response should be sent within the time window starting from the receipt of the identifier from the UE.

[0096] Therefore, by utilizing the response to a successfully completed HO procedure, the UE can avoid link quality degradation due to one or more new PCIs caused by outdated channel measurements when making cell selection decisions, and can improve link quality with the target cell.

[0097] Example communication device

[0098] Figure 9 This illustrates operations that may include being configured to perform the techniques disclosed herein (such as...). Figure 7 The communication device 900 (e.g., corresponding to unit plus functional components) of various components (e.g., the operation shown) in the diagram Figure 1 (UE 120a). The communication device 900 includes a processing system 902 coupled to a transceiver 908 (e.g., a transmitter and / or receiver). The transceiver 908 is configured to transmit and receive signals for the communication device 900 via an antenna 910, such as the various signals described herein. The processing system 902 may be configured to perform processing functions for the communication device 900, including processing signals received and / or to be transmitted by the communication device 900.

[0099] Processing system 902 includes processor 904 coupled to computer-readable medium / memory 912 via bus 906. In some aspects, computer-readable medium / memory 912 is configured to store instructions (e.g., computer-executable code) that, when executed by processor 904, cause processor 904 to perform... Figure 7 The operations shown herein or other operations used to perform the various techniques discussed herein. In some aspects, the computer-readable medium / memory 912 stores: code 914 for receiving signaling of a plurality of candidate target physical cell identifiers (PCIs) for configuring at least one candidate target cell supporting physical (PHY) layer or media access control (MAC) layer mobility signaling; code 916 for participating in a handover process based on PHY layer or MAC layer mobility signaling to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; code 918 for receiving a response message from the target cell indicating the success of the handover process; and code 920 for terminating activity with one or more source PCIs after receiving the response message.

[0100] In some aspects, the processing system 902 has circuitry 922 configured to implement code stored in a computer-readable medium / memory 912. In some aspects, circuitry 922 is coupled to processor 904 and / or computer-readable medium / memory 912 via bus 906. For example, circuitry 922 includes: circuitry 924 for receiving signaling of a plurality of candidate target PCIs configured to support at least one candidate target cell for PHY-layer or MAC-layer mobility signaling; circuitry 926 for participating in a handover process based on PHY-layer or MAC-layer mobility signaling to a target cell associated with one or more selected candidate target PCIs; circuitry 928 for receiving a response message from the target cell indicating the success of the handover process; and circuitry 930 for terminating activity with one or more source PCIs after receiving the response message.

[0101] Figure 10 This illustrates operations that may include being configured to perform the techniques disclosed herein (such as...). Figure 8 The communication device 1000 (e.g., a network entity, such as...) consists of various components (e.g., corresponding to unit plus functional components) of the operation shown in the diagram. Figure 1 (BS 110a). The communication device 1000 includes a processing system 1002 coupled to a transceiver 1008 (e.g., a transmitter and / or receiver). The transceiver 1008 is configured to transmit and receive signals for the communication device 1000, such as the various signals described herein, via an antenna 1010. The processing system 1002 may be configured to perform processing functions of the communication device 1000, including processing signals received and / or to be transmitted by the communication device 1000.

[0102] Processing system 1002 includes processor 1004 coupled to computer-readable medium / memory 1012 via bus 1006. In some aspects, computer-readable medium / memory 1012 is configured to store instructions (e.g., computer-executable code) that, when executed by processor 1004, cause processor 1004 to perform. Figure 8 The operations shown herein or other operations used to perform the various techniques discussed herein. In some aspects, the computer-readable medium / memory 1012 stores: code 1014 for sending to the UE signaling a plurality of candidate target PCIs of at least one candidate target cell that configures PHY-layer or MAC-layer mobility signaling; code 1016 for participating in a handover process based on PHY-layer or MAC-layer mobility signaling, in which the UE is associated with one or more candidate target PCIs selected from the candidate target PCIs; and code 1018 for sending a response message via the target cell indicating the success of the handover process.

[0103] In some aspects, the processing system 1002 has circuitry 1022 configured to implement code stored in a computer-readable medium / memory 1012. In some aspects, circuitry 1022 is coupled to processor 1004 and / or computer-readable medium / memory 1012 via bus 1006. For example, circuitry 1022 includes: circuitry 1024 for sending to the UE signaling a plurality of candidate target PCIs of at least one candidate target cell supporting PHY-layer or MAC-layer mobility signaling; circuitry 1026 for participating in a handover process based on PHY-layer or MAC-layer mobility signaling, whereby the UE moves to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; and circuitry 1028 for sending a response message indicating success of the handover process via the target cell.

[0104] Example

[0105] In addition to the aspects described above, specific combinations of aspects are also within the scope of this disclosure, some of which are described in detail below:

[0106] Aspect 1: A method for wireless communication by a user equipment (UE), comprising: receiving signaling of a plurality of candidate target physical cell identifiers (PCIs) configured to support at least one candidate target cell for physical (PHY) layer or media access control (MAC) layer mobility signaling; participating in a handover process based on the PHY layer or MAC layer mobility signaling to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs; receiving a response message from the target cell indicating success of the handover process; and terminating activity with one or more source PCIs after receiving the response message.

[0107] Aspect 2: According to the method of aspect 1, the response message is transmitted via at least one of downlink control information (DCI) or MAC control element (MAC-CE).

[0108] Aspect 3: The method according to aspect 1 or 2, wherein the activity to be terminated includes at least one of the following: communication with the one or more source PCIs; or monitoring the physical downlink control channel (PDCCH) on the one or more source PCIs.

[0109] Aspect 4: The method according to any one of Aspects 1-3 further includes sending an indication to at least one of the following: the selected one or more candidate target PCIs among the candidate target PCIs; or the one or more source PCIs.

[0110] Aspect 5: The method according to aspect 4, wherein the indication is transmitted via at least one of a Physical Random Access Channel (PRACH) preamble, an uplink reference signal, uplink control information (UCI), or a MAC control element (MAC-CE).

[0111] Aspect 6: The method according to any one of Aspects 1-4, wherein: the handover process is initiated by a network entity; and the network entity indicates the selected one or more candidate target PCIs in a selection command signaled via PHY layer or MAC layer signaling.

[0112] Aspect 7: The method according to aspect 6 further includes, after receiving the selection command: monitoring the physical downlink control channel (PDCCH) on the cell associated with the selected one or more candidate target PCIs among the candidate target PCIs.

[0113] Aspect 8: The method according to aspect 6 or 7, wherein the response message is transmitted via downlink control information (DCI), the DCI being scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

[0114] Aspect 9: The method according to any one of Aspects 6-8, wherein the response message is transmitted within a time window that begins when the selection command is sent from the network entity.

[0115] Aspect 10: The method according to any one of Aspects 6-9 further includes, after receiving the selection command: sending an uplink signal to the target cell as a cell selection request.

[0116] Aspect 11: According to the method of aspect 10, wherein the uplink signal includes at least one of a Physical Random Access Channel (PRACH) preamble, an uplink reference signal, a Physical Uplink Control Channel (PUCCH), or a Physical Uplink Shared Channel.

[0117] Aspect 12: The method according to aspect 10 or 11, wherein the target cell sends the response message after receiving the uplink signal from the UE.

[0118] Aspect 13: The method according to any one of Aspects 1-4 or 6, wherein the handover process is initiated by the UE by: selecting one or more candidate target PCIs among the candidate target PCIs that satisfy the cell selection criteria; and initiating a random access channel (RACH) process with the target cell.

[0119] Aspect 14: According to the method of aspect 13, wherein, for contention-free random access (CFRA) RACH: after sending the RACH preamble, the UE begins to monitor the physical downlink control channel (PDCCH) on the target cell.

[0120] Aspect 15: The method according to aspect 13 or 14, wherein the target cell sends the response message after receiving the RACH preamble from the UE.

[0121] Aspect 16: The method according to aspect 13 or 14, wherein the response message is transmitted via downlink control information (DCI), the DCI being scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

[0122] Aspect 17: The method according to any one of Aspects 13-16, wherein the response message is transmitted within a time window that begins when the selection command is sent from the network entity.

[0123] Aspect 18: The method according to any one of Aspects 13-17, wherein, for a contention-based random access (CBRA) RACH procedure, after sending the RACH preamble, the UE: receives a random access response (RAR) message with scheduling follow-up messages from the target cell; and after receiving the RAR message, sends an indication of its own identifier in an uplink transmission.

[0124] Aspect 19: The method according to aspect 18, wherein the UE indicates its identifier via a radio network temporary identifier (RNTI) assigned to the UE for one or more of the selected candidate target PCIs among the candidate target PCIs.

[0125] Aspect 20: The method according to aspect 18 or 19, wherein the UE receives the response message after sending the indication for the identifier to the target cell.

[0126] Aspect 21: A method for wireless communication by a network entity, comprising: sending signaling to a user equipment (UE) configuring at least one candidate target cell with multiple candidate target physical cell identifiers (PCIs) supporting physical (PHY) layer or media access control (MAC) layer mobility signaling; participating in a handover process based on the PHY layer or MAC layer mobility signaling, wherein the UE is associated with one or more candidate target PCIs selected from the candidate target PCIs; and sending a response message indicating success of the handover process via the target cell.

[0127] Aspect 22: The method according to aspect 21, wherein the response message is transmitted via at least one of downlink control information (DCI) or MAC control element (MAC-CE).

[0128] Aspect 23: The method according to aspect 21 or 22 further includes: receiving an indication from the UE, the indication acknowledging receipt of the response message for at least one of the following: the selected one or more candidate target PCIs among the candidate target PCIs; or the UE having terminated activity with one or more source PCIs.

[0129] Aspect 24: The method according to aspect 23, wherein the indication is transmitted via at least one of: Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

[0130] Aspect 25: According to any one of Aspects 21-23, the handover process is initiated by the network entity; and the network entity indicates the selected one or more candidate target PCIs in a selection command signaled via PHY layer or MAC layer signaling.

[0131] Aspect 26: The method according to aspect 25 further includes, after sending the selection command: sending a physical downlink control channel (PDCCH) via a cell associated with one or more of the selected candidate target PCIs among the candidate target PCIs.

[0132] Aspect 27: The method according to aspect 25 or 26, wherein the response message is transmitted via downlink control information (DCI), the DCI being scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

[0133] Aspect 28: The method according to any one of Aspects 25-27, wherein the response message is transmitted within a time window that begins when the selection command is sent from the network entity.

[0134] Aspect 29. An apparatus comprising a unit for performing the method according to any one of aspects 1-28.

[0135] Aspect 30. A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors of a processing system, cause the processing system to perform the method according to any one of aspects 1-28.

[0136] Aspect 31. A computer program product embodied on a computer-readable storage medium, comprising code for performing the method according to any one of aspects 1-28.

[0137] The techniques described herein can be used in various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are generally used interchangeably. CDMA networks can implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDMA. UTRA and E-UTRA are components of the Global System for Mobile Telecommunications (UMTS). LTE and LTE-A are UMTS versions using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). NR is an emerging wireless communication technology under development.

[0138] The techniques described herein can be used in the wireless networks and radio technologies mentioned above, as well as other wireless networks and radio technologies. Although, for clarity, this document may use terms commonly associated with 3G, 4G, or 5G wireless technologies to describe the aspects, the aspects of this disclosure can be applied to communication systems based on other generations.

[0139] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the term "cell" is used interchangeably with BS, Next Generation Node B (gNB or gNodeB), Access Point (AP), Distributed Unit (DU), and Carrier or Transmitter / Receive Point (TRP). A BS can provide communication coverage for macrocells, picocells, femtocells, or other types of cells. A macrocell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access for UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access for UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a home) and can allow restricted access for UEs associated with the femtocell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of users in a home, etc.). A BS used for a macrocell can be called a macro BS. A BS used for a picocell can be called a pico BS. A BS used for a femtocell can be called a femto BS or a home BS.

[0140] A UE can also be referred to as a mobile station, terminal, access terminal, user unit, station, client equipment (CPE), cellular phone, smartphone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or medical equipment, biometric sensor / device, wearable devices such as smartwatches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets, etc.), entertainment devices (e.g., music devices, video devices, satellite radio devices, etc.), vehicle components or sensors, smart meters / sensors, industrial manufacturing equipment, GPS equipment, or any other suitable device configured to communicate via wireless or wired media. Some UEs can be considered machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that can communicate with a BS, another device (e.g., a remote device), or some other entity. Wireless nodes can provide connectivity to or to a network, for example, via wired or wireless communication links. Some UEs can be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0141] Some wireless networks (e.g., LTE) utilize Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single-Carrier Frequency Division Multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are often referred to as frequency modulation, frequency bands, etc. Each subcarrier can be modulated with data. Typically, modulation symbols are transmitted in the frequency domain using OFDM and in the time domain using SCFDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz, and the minimum resource allocation (called a "resource block" (RB)) can be 12 subcarriers (or 180 kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, the nominal Fast Fourier Transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be divided into subbands. For example, a subband can cover 1.08 MHz (e.g., 6 RBs), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there can be 1, 2, 4, 8, or 16 subbands, respectively. In LTE, the basic transmission time interval (TTI) or packet duration is a 1 ms subframe.

[0142] NR can utilize OFDM with CP on both uplink and downlink, and includes support for half-duplex operation using TDD. In NR, subframes are still 1ms, but the basic TTI is called a slot. Depending on the subcarrier spacing, a subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, ... slots). NR RBs are 12 consecutive frequency subcarriers. NR can support a basic subcarrier spacing of 15kHz, and other subcarrier spacings can be defined with respect to the basic subcarrier spacing, such as 30kHz, 60kHz, 120kHz, 240kHz, etc. Symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing. Beamforming can be supported, and beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. In some examples, MIMO configurations in DL can support up to 8 transmit antennas, with up to 8 streams in multilayer DL transmission and up to 2 streams per UE. In some examples, multilayer transmission with up to 2 streams per UE can be supported. It can support aggregation of multiple cells with up to 8 serving cells.

[0143] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entity utilizes the resources allocated by the scheduling entity. A base station is not the only entity that can act as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs can utilize the resources scheduled by that UE for wireless communication. In some examples, a UE can act as a scheduling entity in a peer-to-peer (P2P) network or a mesh network. In mesh network examples, in addition to communicating with a scheduling entity, UEs can also communicate directly with each other.

[0144] As used herein, the term "determine" can encompass one or more of a wide variety of actions. For example, "determine" can include calculation, operation, processing, derivation, investigation, lookup (e.g., searching in a table, database, or other data structure), hypothesis, etc. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Additionally, "determine" can include parsing, selecting, picking, building, etc.

[0145] As used herein, unless otherwise expressly stated, “or” is intended to be interpreted in an inclusive sense. For example, “a or b” could include only a, only b, or a combination of a and b. As used herein, phrases referring to “at least one” or “one or more” of a list of items refer to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover the possibilities of only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0146] The various operations described above can be performed by any suitable unit capable of performing the corresponding function. These units may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors. Typically, where the operations shown in the accompanying drawings exist, those operations may have corresponding units plus functional components. For example, Figure 7 and 8 The various operations shown can be performed by Figure 2 The various processors shown execute this.

[0147] The various exemplary logic blocks, modules, and circuits described in connection with this disclosure may be implemented or executed using a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but alternatively, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0148] If implemented in hardware, an example hardware configuration could include a processing system in a wireless node. The processing system could be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus could include any number of interconnect buses and bridges. The bus could link together various circuits, including a processor, machine-readable media, and a bus interface. The bus interface could be used to connect network adapters, etc., to the processing system via the bus. The network adapter could be used to implement signal processing functions at the PHY layer. In UE 120 (see...) Figure 1 In this case, a user interface (e.g., keyboard, display, mouse, joystick, etc.) can also be connected to the bus. The bus can also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor can be implemented using one or more general-purpose and / or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how the described functions of the processing system can be optimally implemented based on the specific application and the overall design constraints imposed on the system as a whole.

[0149] If implemented in software, the functionality can be stored or transmitted as one or more instructions or code on or through a computer-readable medium. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted to mean instructions, data, or any combination thereof. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates the transmission of a computer program from one location to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on the machine-readable storage medium. The computer-readable storage medium may be coupled to the processor, allowing the processor to read information from and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor. As an example, the machine-readable medium may include a transmission line, a carrier wave modulated by data, and / or a separate computer-readable storage medium on which instructions are stored, all accessible to the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any portion thereof may be integrated into the processor, for example, in this case, into a cache and / or a general-purpose register file. As an example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, disks, optical disks, hard disks, or any other suitable storage media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0150] Software modules may include a single instruction or many instructions, and may be distributed across several different code segments, across different programs, and across multiple storage media. Computer-readable media may include multiple software modules. Software modules include instructions that, when executed by a device such as a processor, cause the processing system to perform various functions. Software modules may include transfer modules and receive modules. Each software module may reside in a single storage device or be distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard disk drive into RAM. During the execution of a software module, the processor may load some of the instructions into a cache to improve access speed. One or more cache lines may then be loaded into a general-purpose register file for processor execution. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.

[0151] Furthermore, any connection is appropriately referred to as computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disks and optical discs include compact optical discs (CDs), laser discs, optical discs, digital versatile optical discs (DVDs), floppy disks, and... Optical discs, where magnetic disks typically copy data magnetically, use lasers to optically copy data. Therefore, in some aspects, computer-readable media can include non-transitory computer-readable media (e.g., tangible media). Additionally, in other aspects, computer-readable media can include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0152] Therefore, certain aspects may include computer program products for performing the operations described herein. For example, such computer program products may include computer-readable media on which instructions are stored (and / or encoded) that can be executed by one or more processors to perform the operations described herein. Figure 7-10 The instructions for the operation are shown in the figure.

[0153] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the embodiments shown herein, but are to be given the widest scope consistent with this disclosure, the principles disclosed herein, and the novel features.

[0154] Furthermore, the various features described in this specification in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Thus, although features may be described above as functioning in a particular combination, and even initially claimed in this way, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may be for sub-combinations or variations thereof.

[0155] Similarly, although operations are shown in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or to perform all shown operations to achieve the desired result. Furthermore, the drawings may schematically illustrate one or more example processes in the form of flowcharts or block diagrams. However, other operations not shown may be incorporated into the schematically shown example processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the shown operations. In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: Receive signaling, the signaling configuration supporting at least one candidate target physical cell identifier (PCI) for a candidate target cell that supports physical PHY layer or media access control (MAC layer) mobility signaling; A selection command is received via PHY layer or MAC layer signaling, the selection command indicating one or more candidate target PCIs to be selected from the candidate target PCIs; After receiving the selection command, an uplink signal is sent to the target cell as a cell selection request; Based on PHY or MAC layer mobility signaling, participate in the handover process of the target cell associated with one or more candidate target PCIs selected from the candidate target PCIs, wherein the handover process is initiated by a network entity; Receive a response message from the target cell indicating the success of the handover process; and Upon receiving the response message, the activity with one or more source PCIs is terminated.

2. The method according to claim 1, wherein, The response message is transmitted via at least one of Downlink Control Information (DCI) or MAC Control Element (MAC-CE).

3. The method according to claim 1, wherein, The terminated activity includes at least one of the following: Communication with one or more source PCIs; or Monitor the Physical Downlink Control Channel (PDCCH) on one or more source PCIs.

4. The method of claim 1, further comprising sending an indication acknowledging receipt of the response message to at least one of the following: The selected one or more candidate target PCIs among the candidate target PCIs; or The one or more source PCIs.

5. The method according to claim 4, wherein, The indication is transmitted via at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

6. The method according to claim 1, further comprising, after receiving the selection command: Monitor the physical downlink control channel (PDCCH) on the cell associated with one or more of the selected candidate target PCIs in the candidate target PCIs.

7. The method according to claim 1, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

8. The method according to claim 1, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

9. The method according to claim 1, wherein, The uplink signal includes at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, Physical Uplink Control Channel (PUCCH), or Physical Uplink Shared Channel.

10. The method according to claim 1, wherein, The target cell sends the response message after receiving the uplink signal from the UE.

11. The method according to claim 1, wherein, The handover process is initiated by the UE in the following manner: Select one or more candidate target PCIs from the candidate target PCIs that meet the cell selection criteria; and Initiate a random access channel (RACH) procedure with the target cell.

12. The method according to claim 11, wherein, For Contention-Free Random Access (CFRA) RACH: After sending the RACH preamble, the UE begins monitoring the Physical Downlink Control Channel (PDCCH) on the target cell.

13. The method according to claim 12, wherein, The target cell sends the response message after receiving the RACH preamble from the UE.

14. The method according to claim 11, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

15. The method according to claim 11, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

16. The method according to claim 11, wherein, For a contention-based random access (CBRA) RACH procedure, after sending the RACH preamble, the UE: Receive a Random Access Response (RAR) message from the target cell to receive subsequent scheduling messages; as well as Upon receiving the RAR message, an indication of its own identifier is sent during uplink transmission.

17. The method according to claim 16, wherein, The UE indicates its identity via a Radio Network Temporary Identifier (RNTI) assigned to the UE for one or more of the selected candidate target PCIs.

18. The method according to claim 16, wherein, The UE receives the response message after sending the indication for the identifier to the target cell.

19. A method for wireless communication by a network entity, comprising: Sending signaling to the user equipment (UE) to configure multiple candidate target physical cell identifiers (PCIs) of at least one candidate target cell that support mobility signaling at the physical PHY layer or medium access control (MAC) layer; A selection command is sent to the UE via PHY layer or MAC layer signaling, the selection command indicating one or more candidate target PCIs selected from the candidate target PCIs; After sending the selection command, the uplink signal is received from the UE via the target cell as a cell selection request. Based on PHY or MAC layer mobility signaling, participate in the handover process of the UE to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs, wherein the handover process is initiated by a network entity; Send a response message indicating the success of the handover process via the target cell; and The indication is received directly from the UE as follows, confirming receipt of the response message: One or more candidate target PCIs selected from the candidate target PCIs, or The UE has terminated its activity with one or more source PCIs.

20. The method according to claim 19, wherein, The response message is transmitted via at least one of Downlink Control Information (DCI) or MAC Control Element (MAC-CE).

21. The method according to claim 19, wherein, The indication is transmitted via at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

22. The method of claim 19, further comprising, after sending the selection command: The physical downlink control channel (PDCCH) is transmitted via the cell associated with one or more of the selected candidate target PCIs in the candidate target PCIs.

23. The method according to claim 19, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

24. The method according to claim 19, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

25. The method according to claim 19, wherein, The uplink signal includes at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, Physical Uplink Control Channel (PUCCH), or Physical Uplink Shared Channel.

26. The method according to claim 19, wherein, The target cell sends the response message after receiving the uplink signal from the UE.

27. An apparatus for wireless communication by a user equipment (UE), comprising: One or more processors coupled to the memory, said one or more processors being configured to perform the following operations individually or in combination: Receive signaling, the signaling configuration supporting at least one candidate target physical cell identifier (PCI) for a candidate target cell that supports physical PHY layer or media access control (MAC layer) mobility signaling; A selection command is received via PHY layer or MAC layer signaling, the selection command indicating one or more candidate target PCIs to be selected from the candidate target PCIs; After receiving the selection command, an uplink signal is sent to the target cell as a cell selection request; Based on PHY or MAC layer mobility signaling, participate in the handover process of the target cell associated with one or more candidate target PCIs selected from the candidate target PCIs, wherein the handover process is initiated by a network entity; Receive a response message from the target cell indicating the success of the handover process; and Upon receiving the response message, the activity with one or more source PCIs is terminated.

28. The apparatus according to claim 27, wherein, The response message is transmitted via at least one of Downlink Control Information (DCI) or MAC Control Element (MAC-CE).

29. The apparatus according to claim 27, wherein, The terminated activity includes at least one of the following: Communication with one or more source PCIs; or Monitor the Physical Downlink Control Channel (PDCCH) on one or more source PCIs.

30. The apparatus according to claim 27, wherein, The one or more processors are further configured to perform the following operations individually or in combination: Send an indication confirming receipt of the response message to at least one of the following: The selected one or more candidate target PCIs among the candidate target PCIs; or The one or more source PCIs.

31. The apparatus according to claim 30, wherein, The indication is transmitted via at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

32. The apparatus according to claim 27, wherein, The one or more processors are further configured to perform the following operations individually or in combination: After receiving the selection command: Monitor the physical downlink control channel (PDCCH) on the cell associated with one or more of the selected candidate target PCIs in the candidate target PCIs.

33. The apparatus according to claim 27, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

34. The apparatus according to claim 27, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

35. The apparatus according to claim 27, wherein, The uplink signal includes at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, Physical Uplink Control Channel (PUCCH), or Physical Uplink Shared Channel.

36. The apparatus according to claim 27, wherein, The target cell sends the response message after receiving the uplink signal from the UE.

37. The apparatus according to claim 27, wherein, The handover process is initiated by the UE in the following manner: Select one or more candidate target PCIs from the candidate target PCIs that meet the cell selection criteria; and Initiate a random access channel (RACH) procedure with the target cell.

38. The apparatus according to claim 37, wherein, For Contention-Free Random Access (CFRA) RACH: After sending the RACH preamble, the UE begins monitoring the Physical Downlink Control Channel (PDCCH) on the target cell.

39. The apparatus according to claim 38, wherein, The target cell sends the response message after receiving the RACH preamble from the UE.

40. The apparatus according to claim 37, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

41. The apparatus according to claim 37, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

42. The apparatus according to claim 37, wherein, For a contention-based random access (CBRA) RACH procedure, after sending the RACH preamble, the UE: Receive a Random Access Response (RAR) message from the target cell to receive subsequent scheduling messages; as well as Upon receiving the RAR message, an indication of its own identifier is sent during uplink transmission.

43. The apparatus according to claim 42, wherein, The UE indicates its identity via a Radio Network Temporary Identifier (RNTI) assigned to the UE for one or more of the selected candidate target PCIs.

44. The apparatus according to claim 42, wherein, The UE receives the response message after sending the indication for the identifier to the target cell.

45. An apparatus for wireless communication by a network entity, comprising: One or more processors coupled to the memory, said one or more processors being configured to perform the following operations individually or in combination: Sending signaling to the user equipment (UE) to configure multiple candidate target physical cell identifiers (PCIs) of at least one candidate target cell that support mobility signaling at the physical PHY layer or medium access control (MAC) layer; A selection command is sent to the UE via PHY layer or MAC layer signaling, the selection command indicating one or more candidate target PCIs selected from the candidate target PCIs; After sending the selection command, the uplink signal is received from the UE via the target cell as a cell selection request. Based on PHY or MAC layer mobility signaling, participate in the handover process of the UE to a target cell associated with one or more candidate target PCIs selected from the candidate target PCIs, wherein the handover process is initiated by a network entity; Send a response message indicating the success of the handover process via the target cell; and The indication is received directly from the UE as follows, confirming receipt of the response message: One or more candidate target PCIs selected from the candidate target PCIs, or The UE has terminated its activity with one or more source PCIs.

46. ​​The apparatus according to claim 45, wherein, The response message is transmitted via at least one of Downlink Control Information (DCI) or MAC Control Element (MAC-CE).

47. The apparatus according to claim 45, wherein, The indication is transmitted via at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, uplink control information (UCI), or MAC control element (MAC-CE).

48. The apparatus according to claim 45, wherein, The one or more processors are further configured to perform the following operations individually or in combination: After sending the selection command: The physical downlink control channel (PDCCH) is transmitted via the cell associated with one or more of the selected candidate target PCIs in the candidate target PCIs.

49. The apparatus according to claim 45, wherein, The response message is transmitted via downlink control information (DCI), which is scrambled by a radio network temporary identifier (RNTI) assigned to the UE for one or more candidate target PCIs selected from the candidate target PCIs.

50. The apparatus according to claim 45, wherein, The response message is transmitted within a time window that begins when the network entity sends the selection command.

51. The apparatus according to claim 45, wherein, The uplink signal includes at least one of the following: Physical Random Access Channel (PRACH) preamble, uplink reference signal, Physical Uplink Control Channel (PUCCH), or Physical Uplink Shared Channel.

52. The apparatus according to claim 45, wherein, The target cell sends the response message after receiving the uplink signal from the UE.

53. A computer-readable medium having instructions stored thereon for causing a user equipment (UE) to perform the method according to any one of claims 1-18.

54. A computer-readable medium having instructions stored thereon for causing a network entity to perform the method according to any one of claims 19-26.

55. An apparatus for wireless communication by a user equipment (UE), comprising: Units for performing the steps of the method according to any one of claims 1-18.

56. An apparatus for wireless communication by a network entity, comprising: Units for performing the steps of the method according to any one of claims 19-26.

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