Reference measurement timing selection for wireless communication mobility

Abstract

Various aspects relate to selecting a physical cell identifier (PCI) for a user equipment (UE) to use to obtain a timing reference for mobility measurements. A serving base station (BS) associated with multiple cells may select a set of these cells as candidate cells for the UE and send a set of candidate PCIs associated with those cells to the UE (e.g., one PCI for each cell). The BS may select a subset of the candidate cells to serve the UE and indicate the corresponding PCI subset to the UE. The UE may select a PCI from the set of candidate PCIs (or from the subset of PCIs) for obtaining a timing reference for synchronization signal block (SSB) measurements. The UE may select a PCI based on defined rules. The UE may select a PCI based on signaling from a BS.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to and the benefit of co-pending nonprovisional application No. 17 / 202,944 filed in the U.S. Patent and Trademark Office on March 16, 2021, and provisional application No. 63 / 015,365 filed in the U.S. Patent and Trademark Office on April 24, 2020, and is assigned to the assignee hereof, which are hereby expressly incorporated herein by reference as if set forth in their entirety and for all applicable purposes as follows. Technical Field

[0003] The techniques discussed below relate generally to wireless communications and, more particularly, to selecting a reference measurement timing for mobility operations. Background Art

[0004] A next generation wireless communication system (e.g., 5GS) may include a 5G core network and a 5G radio access network (RAN), such as a new radio (NR)-RAN. The NR-RAN supports communication through one or more cells. For example, a wireless communication device such as a user equipment (UE) may access a first cell of a first base station (BS) such as a gNB and / or access a second cell of a second BS.

[0005] The network may support mobility operations that enable a UE to communicate with one or more nearby cells. For example, when a UE moves through a service area of ​​the network, a handover may occur such that the UE initially communicates with at least one cell and then communicates with at least one other cell. Summary of the invention

[0006] An overview of one or more aspects of the present disclosure is presented below in order to provide a basic understanding of these aspects. This overview is not an extensive overview of all expected features of the present disclosure, and is neither intended to identify the key or critical elements of all aspects of the present disclosure, nor is it intended to delineate the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in a form as a prelude to a more detailed description presented later.

[0007] In some examples, the present disclosure provides a method for wireless communication at a user equipment. The method may include: receiving a first indication of a set of candidate physical cell identifiers (PCIs) of the user equipment from a base station; selecting a first PCI from the set of candidate PCIs; determining a timing reference for synchronization signal block (SSB) measurement from a downlink reception timing associated with the first PCI; and performing SSB measurement using the timing reference.

[0008] In some examples, the present disclosure provides a user equipment, including a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory. The processor and the memory may be configured to receive a first indication of a set of candidate physical cell identifiers (PCIs) of the user equipment from a base station via the transceiver; select a first PCI from the set of candidate PCIs; determine a timing reference for a synchronization signal block (SSB) measurement from a downlink reception timing associated with the first PCI; and perform SSB measurement using the timing reference.

[0009] In some examples, the present disclosure provides a user equipment. The user equipment may include: a component for receiving a first indication of a set of candidate physical cell identifiers (PCIs) of the user equipment from a base station; a component for selecting a first PCI from the set of candidate PCIs; a component for determining a timing reference for synchronization signal block (SSB) measurement from a downlink reception timing associated with the first PCI; and a component for performing SSB measurement using the timing reference.

[0010] In some examples, the present disclosure provides an article for use with a user device. The article may include a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of the user device to receive a first indication of a set of candidate physical cell identifiers (PCIs) of the user device from a base station; select a first PCI from the set of candidate PCIs; determine a timing reference for synchronization signal block (SSB) measurement from a downlink reception timing associated with the first PCI; and perform SSB measurement using the timing reference.

[0011] In some examples, the present disclosure provides a method for wireless communication at a base station. The method may include: sending a physical cell identifier (PCI) selection indication to a user equipment. The PCI selection indication may specify a selection process for selecting a timing reference associated with the PCI for synchronization signal block (SSB) measurement. The method may also include receiving a measurement report from the user equipment after sending the PCI selection indication; and performing mobility operations on the user equipment based on the measurement report.

[0012] In some examples, the present disclosure provides a base station, including a transceiver; a memory; and a processor, communicatively coupled to the transceiver and the memory. The processor and the memory may be configured to send a physical cell identifier (PCI) selection indication to a user equipment via the transceiver. The PCI selection indication may specify a selection process for selecting a timing reference associated with the PCI for synchronization signal block (SSB) measurement. The processor and the memory may also be configured to receive a measurement report from the user equipment via the transceiver after sending the PCI selection indication; and perform mobility operations on the user equipment based on the measurement report.

[0013] In some examples, the present disclosure provides a base station. The base station may include a component for sending a physical cell identifier (PCI) selection indication to a user equipment. The PCI selection indication specifies a selection process for selecting a timing reference associated with the PCI for synchronization signal block (SSB) measurement. The base station may also include a component for receiving a measurement report from the user equipment after sending the PCI selection indication; and a component for performing mobility operations on the user equipment based on the measurement report.

[0014] In some examples, the present disclosure provides an article for use with a base station. The article may include a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of a user device to send a physical cell identifier (PCI) selection indication to the user device. The PCI selection indication may specify a selection process for selecting a timing reference associated with the PCI for synchronization signal block (SSB) measurement. The computer-readable medium may also store therein instructions executable by one or more processors of the base station to receive a measurement report from the user device after sending the PCI selection indication; and perform mobility operations on the user device based on the measurement report.

[0015] These and other aspects of the present disclosure will become more fully understood after reading the detailed description below. After reading the following description of the specific example aspects of the present disclosure in conjunction with the accompanying drawings, other aspects, features and examples of the present disclosure will become clear to those of ordinary skill in the art. Although the features of the present disclosure can be discussed with respect to certain examples and drawings below, all examples of the present disclosure can include one or more advantageous features discussed herein. In other words, although one or more examples can be discussed as having certain advantageous features, one or more of these features can also be used according to the various examples of the present disclosure discussed herein. In a similar manner, although the example aspects can be discussed below as device, system or method examples, it should be understood that such example aspects can be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a wireless communication system according to some aspects.

[0017] Figure 2 is a conceptual illustration of an example of a radio access network in accordance with some aspects.

[0018] Figure 3 is a diagram of wireless resources in an air interface utilizing orthogonal frequency division multiplexing (OFDM) according to some aspects.

[0019] Figure 4A is a diagram illustrating an example of a frame structure for a synchronization signal in a wireless communication network according to some aspects.

[0020] Figure 4B is a diagram illustrating an example of a portion of a frame or subframe structure having various channels and associated messages for use in a wireless communication network in accordance with some aspects.

[0021] Figure 5 is a diagram of an example of multiple serving cells in accordance with some aspects.

[0022] Figure 6 is a diagram of an example of a wireless communication system in accordance with some aspects.

[0023] Figure 7 is a diagram of another example of a wireless communication system in accordance with some aspects.

[0024] Figure 8 is a signaling diagram illustrating one example of signaling associated with selecting a timing reference in accordance with some aspects.

[0025] Fig. 9 is a signaling diagram illustrating another example of signaling associated with selecting a timing reference in accordance with some aspects.

[0026] Fig.10 is a block diagram conceptually illustrating an example of a hardware implementation for a user device employing a processing system according to some aspects.

[0027] Fig.11 is a flow chart illustrating an example method involving reference measurement timing selection in accordance with some aspects.

[0028] Fig.12 is a flow chart illustrating an example PCI selection method based on a PCI selection indication according to some aspects.

[0029] Fig.13 is a block diagram conceptually illustrating an example of a hardware implementation for a base station employing a processing system according to some aspects.

[0030] Fig.14 is a flow chart illustrating an example wireless communication mobility method according to some aspects.

[0031] Fig.15 is a flow chart illustrating an example timing reference selection method according to some aspects. DETAILED DESCRIPTION

[0032] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it is clear to those skilled in the art that these concepts may be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obfuscating these concepts.

[0033] Although aspects and examples are described in this application by way of illustration of some examples, it will be understood by those skilled in the art that additional implementations and use cases may occur 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, various aspects and / or uses may be implemented via integrated chip examples and other devices based on non-module components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial devices, retail / procurement devices, medical devices, devices supporting artificial intelligence (AI-enabled), etc.). Although some examples may or may not be specifically targeted at use cases or applications, various applicability of the described innovations may occur. The scope of implementation may range from chip-level or modular components to non-modular, non-chip-level implementations, to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some actual settings, in order to implement and practice the examples claimed and described, the devices incorporating the various aspects and features described may also have to include additional components and features. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). It is intended that the innovations described herein can be practiced in devices of various sizes, shapes, and configurations, chip-level components, systems, distributed arrangements, end-user devices, etc.

[0034] Various aspects of the present disclosure relate to determining the timing of reference measurements for mobility operations. In some networks, a UE may be connected to several cells and / or several transmit and receive points (TRPs) simultaneously. For example, a base station may be configured to serve several cells, or may be configured with several remotely deployed TRPs (e.g., each TRP includes a radio head and at least one antenna) to extend the coverage of the base station. Each cell or transmit and receive point (TRP) may use a unique (e.g., locally unique) physical cell identifier (PCI).

[0035] The base station can configure a set of candidate PCIs for the UE (e.g., PCIs of nearby cells and / or TRPs that are candidates for serving the UE). In addition, the base station can select a subset of candidate PCIs and send an indication of the subset to the UE. For example, based on signal measurements performed by the UE and reported to the base station, the base station can determine a specific (e.g., designated) subset of cells and / or TRPs that are most suitable for serving the UE at this time. This selection can be based on different criteria in different scenarios. As an example, the base station can select the number of PCIs to be included in the subset based on the current business needs of the UE. As another example, the base station can select the PCIs to be included in the subset based on the received signal strength measured by the UE (e.g., the PCIs of cells and / or TRPs associated with the four highest received signal strengths can be included in the subset).

[0036] The present disclosure in some aspects relates to selecting a PCI from a set of candidate PCIs that the UE will use to determine a timing reference for mobility measurements. For example, the UE may select a PCI from a subset of PCIs identified by a base station and measure a downlink signal based on the PCI. The UE may then determine a timing reference from the measured downlink signal and use the timing reference for synchronization signal block (SSB) measurements. In some examples, the UE may select a PCI based on defined rules. In some examples, the UE may select a PCI based on signaling from a serving base station.

[0037] The various concepts presented throughout this disclosure may be implemented across a variety of telecommunication systems, network architectures and communication standards. Figure 1 , various aspects of the present disclosure are described with reference to a wireless communication system 100 as a non-limiting illustrative example. The wireless communication system 100 includes three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. With the wireless communication system 100, the UE 106 can be enabled to communicate data with an external data network 110 such as (but not limited to) the Internet.

[0038] The RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to the UE 106. As an example, the RAN 104 may operate in accordance with the 3rd Generation Partnership Project (3GPP) New Radio (NR) specification, commonly referred to as 5G. As another example, the RAN 104 may operate under a mix of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, commonly referred to as Long Term Evolution (LTE). 3GPP refers to this hybrid RA as the Next Generation RAN, or NG-RAN. In another example, the RAN 104 may operate in accordance with both LTE and 5G NR standards. Of course, many other examples may be used within the scope of the present disclosure.

[0039] As shown, RAN 104 includes multiple base stations 108. Broadly speaking, a base station is a network element in a radio access network, responsible for radio transmission and reception to or from a UE in one or more cells. In different technologies, standards or contexts, a base station may be referred to as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), a node B (NB), an eNode B (eNB), a gNode B (gNB), a transmission and reception point (TRP) or some other suitable terminology by those skilled in the art. In some examples, a base station may include two or more TRPs that may be collocated or non-collocated. Each TRP may communicate on the same or different carrier frequencies in the same or different frequency bands. In an example where RAN 104 operates according to both LTE and 5G NR standards, one of base stations 108 may be an LTE base station, and another base station may be a 5G NR base station.

[0040] The radio access network 104 is further illustrated as supporting wireless communications for multiple mobile devices. The mobile device may be referred to as a user equipment (UE) 106 in the 3GPP standard, but may also be referred to as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology by a person skilled in the art. The UE 106 may be a device that provides access to network services to a user. In an example where the RAN 104 operates according to both LTE and 5G NR standards, the UE 106 may be an Evolved Universal Terrestrial Radio Access Network-New Radio Dual Connectivity (EN-DC) UE capable of simultaneously connecting to an LTE base station and an NR base station to receive packets from both the LTE base station and the NR base station.

[0041] In this document, a mobile device does not necessarily need to have the ability to move and can be national. The term mobile device or mobile device refers to a wide range of devices and technologies. A UE may include many hardware structural components whose size, shape, and arrangement facilitate communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. that are electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile phones, cellular (cell) phones, smart phones, session initiation protocol (SIP) phones, laptops, personal computers (PCs), notebook computers, netbooks, smart books, tablets, personal digital assistants (PDAs), and various embedded systems, for example, corresponding to the Internet of Things (IoT).

[0042] The mobile device may also be a car or other vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multirotor, a quadcopter, a remote control device, a consumer and / or wearable device such as glasses, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., an MP3 player), a camera, a game console, etc. The mobile device may also be a digital home or smart home device such as home audio, video, and / or multimedia devices, appliances, vending machines, smart lighting, home security systems, smart meters, etc. The mobile device may also be a smart energy device, a security device, a solar panel or solar array, municipal infrastructure equipment that controls power (e.g., smart grid), lighting, water, etc., industrial automation and enterprise equipment, logistics controllers, agricultural equipment, etc. In addition, the mobile device may provide connected medical or telemedicine support, i.e., healthcare at a distance. Remote health devices may include remote health monitoring devices and remote health management devices, whose communications may be given priority or access relative to other types of information, for example, in terms of priority access to transmission of critical service data and / or associated QoS for transmission of critical service data.

[0043] Wireless communication between RAN 104 and UE 106 can be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) can be referred to as downlink (DL) transmissions. In some examples, the term downlink can refer to point-to-multipoint transmissions originating from a base station (e.g., base station 108). Another way to describe this point-to-multipoint transmission scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) can be referred to as uplink (UL) transmissions. In some examples, the term uplink can refer to point-to-point transmissions originating from a UE (e.g., UE 106).

[0044] In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station 108) allocates resources for communication between some or all devices and equipment within its service area or cell. In the present disclosure, as discussed further below, a scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more scheduled entities (e.g., UEs). That is, for scheduled communications, multiple UEs 106, which may be scheduled entities, may utilize resources allocated by the scheduling entity 108.

[0045] Base station 108 is not the only entity that can act as a scheduling entity. That is, in some examples, a UE can act as a scheduling entity to schedule resources for one or more scheduled entities (e.g., one or more other UEs). For example, a UE can communicate with other UEs in a peer-to-peer or device-to-device manner and / or in a relay configuration.

[0046] like Figure 1 As shown, the scheduling entity 108 can broadcast downlink traffic 112 to one or more scheduling entities 106. In a broad sense, the scheduling entity 108 is a node or device responsible for scheduling traffic in the wireless communication network, including downlink traffic 112, and in some examples, uplink traffic 116 and / or uplink control information 118 from one or more scheduled entities 106 to the scheduling entity 108. On the other hand, the scheduling entity 106 is a node or device that receives downlink control information 114, including but not limited to scheduling information (e.g., grants), synchronization or timing information, or other control information from another entity in the wireless communication network (such as the scheduling entity 108).

[0047] In addition, uplink and / or downlink control information and / or traffic information may be divided into frames, subframes, time slots and / or symbols by time. As used herein, a symbol may refer to a time unit in which each subcarrier carries a resource element (RE) in an orthogonal frequency division multiplexing (OFDM) waveform. In some examples, a time slot may carry 7 or 14 OFDM symbols. A subframe may refer to a duration of 1 millisecond (ms). Multiple subframes or time slots may be combined to form a single frame or radio frame. In the present disclosure, a frame may refer to a predetermined duration (e.g., 10ms) for wireless transmission, each frame being composed of, for example, 10 subframes of 1ms each. Of course, these definitions are not required, and any suitable scheme for organizing waveforms may be used, and the various time divisions of waveforms may have any suitable duration.

[0048] Typically, the base stations 108 may include a backhaul interface for communicating with a backhaul portion 120 of the wireless communication system. The backhaul 120 may provide a link between the base stations 108 and the core network 102. Additionally, in some examples, the backhaul network may provide interconnections between the various base stations 108. Various types of backhaul interfaces may be employed, such as a direct physical connection using any suitable transport network, a virtual network, and the like.

[0049] The core network 102 may be part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to a 5G standard (e.g., 5GC). In other examples, the core network 102 may be configured according to a 4G Evolved Packet Core (EPC) or any other suitable standard or configuration.

[0050] Reference now Figure 2 , a schematic diagram of RAN 200 is provided as an example and not as a limitation. In some examples, RAN 200 may be used in conjunction with the above-described Figure 1 The RAN 104 shown is the same.

[0051] The geographic area covered by the RAN 200 may be divided into cellular areas (cells) that may be uniquely identified by a user equipment (UE) based on an identity broadcast from an access point or base station. Figure 2 The cells 202, 204, 206 and 208 are shown, each of which may include one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a cell are served by the same base station. A radio link within a sector may be identified by a single logical identifier belonging to the sector. In a cell divided into sectors, multiple sectors within a cell may be formed by antenna groups, each antenna being responsible for communicating with a UE in a portion of the cell.

[0052] Various base station arrangements can be used. Figure 2 , two base stations 210 and 212 are shown in cells 202 and 204; a third base station 214 is shown as controlling a remote radio head (RRH) 216 in cell 206. That is, the base station may have an integrated antenna or may be connected to an antenna or RRH via a feeder cable. In the example shown, cells 202, 204, and 206 may be referred to as macro cells because base stations 210, 212, and 214 support cells with large sizes. In addition, a base station 218 is shown in cell 208, which may overlap with one or more macro cells. In this example, cell 208 may be referred to as a small cell (e.g., a micro cell, a pico cell, a femto cell, a home base station, a home node B, a home eNode B, etc.) because base station 218 supports a cell with a relatively small size. The cell size may be determined based on the system design and component constraints.

[0053] It should be understood that the radio access network 200 may include any number of wireless base stations and cells. In addition, relay nodes may be deployed to extend the size or coverage area of ​​a given cell. Base stations 210, 212, 214, 218 provide wireless access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and / or 218 may be similar to those described above and Figure 1 The base stations / scheduling entities 108 shown are identical.

[0054] Figure 2 Also included is an unmanned aerial vehicle (UAV) 220, which may be a drone or a quadcopter. UAV 220 may be configured to function as a base station, or more specifically as a mobile base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of ​​a cell may move depending on the location of a mobile base station (such as UAV 220).

[0055] Within the RAN 200, cells may include UEs that may communicate with one or more sectors of each cell. In addition, each base station 210, 212, 214, and 218 may be configured to provide a core network 102 (see FIG. 1 ) for all UEs in the corresponding cell. Figure 1 ) access point. For example, UEs 222 and 224 may communicate with base station 210; UEs 226 and 228 may communicate with base station 212; UEs 230 and 232 may communicate with base station 214 via RRH 216; and UE 234 may communicate with base station 218. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and / or 242 may communicate with the base stations described above and in Figure 1 200. In some examples, UAV 220 (e.g., a quadcopter) may be a mobile network node and may be configured to function as a UE. For example, UAV 220 may operate within cell 202 by communicating with base station 210.

[0056] On the other hand of RAN 200, side link signals can be used between UEs without relying on scheduling or control information from a base station. For example, side link communications can be used in a device-to-device (D2D) network, a peer-to-peer (P2P) network, a vehicle-to-vehicle (V2V) network, a vehicle-to-everything (V2X) network, and / or other suitable side link networks. For example, two or more UEs (e.g., UE 238, 240, and 242) can communicate with each other using side link signals 237 without relaying the communication through a base station. In some examples, UE 238, 240, and 242 can each act as a scheduling entity or a transmitting side link device and / or a scheduled entity or a receiving side link device to schedule resources and transmit side link signals 237 therebetween without relying on scheduling or control information from a base station. In other examples, two or more UEs (e.g., UE 226 and 228) within the coverage area of ​​a base station (e.g., base station 212) can also transmit side link signals 227 via a direct link (side link) without transmitting the communication through base station 212. In this example, base station 212 may allocate resources to UEs 226 and 228 for sidelink communications.

[0057] In the radio access network 200, the ability of a UE to communicate while moving, regardless of its location, is called mobility. The various physical channels between the UE and the radio access network are typically managed by an access and mobility management function (AMF, not shown). Figure 1 The security context management function (SCMF) is established, maintained and released under the control of the core network 102 (part of the core network 102 in the core network), which may include a security context management function (SCMF) that manages the security context of control plane and user plane functions, and a security anchor function (SEAF) that performs authentication.

[0058] The radio access network 200 may utilize DL-based mobility or UL-based mobility to implement mobility and handover (i.e., transferring a UE's connection from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of a signal from its serving cell and various parameters of neighboring cells. Based on the quality of these parameters, the UE may maintain communication with one or more neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from a neighboring cell exceeds the signal quality from the serving cell for a given time, the UE may perform a handover from the serving cell to a neighboring cell or (target) cell. For example, a UE 224 (illustrated as a vehicle, although any suitable form of UE may be used) may move from a geographic area corresponding to its serving cell 202 to a geographic area corresponding to a neighboring cell 206. When the signal strength or quality from a neighboring cell 206 exceeds the signal strength and quality of the serving cell 202 for a given amount of time, the UE 224 may send a report message to its serving base station 210 indicating this condition. In response, UE 224 may receive a handover command, and the UE may undergo a handover to cell 206 .

[0059] In a network configured for UL-based mobility, the UL reference signal from each UE can be used by the network to select a serving cell for each UE. In some examples, base stations 210, 212, and 214 / 216 can broadcast a unified synchronization signal (e.g., a unified primary synchronization signal (PSS), a unified secondary synchronization signal (SSS), and a unified physical broadcast channel (PBCH)). UE 222, 224, 226, 228, 230, and 232 can receive a unified synchronization signal, derive carrier frequency and slot timing from the synchronization signal, and send an uplink pilot or reference signal in response to the derived timing. The uplink pilot signal sent by the UE (e.g., UE 224) can be received simultaneously by two or more cells (e.g., base stations 210 and 214 / 216) within the radio access network 200. Each cell can measure the strength of the pilot signal, and the radio access network (e.g., one or more of base stations 210 and 214 / 216 and / or a central node within the core network) can determine the serving cell for UE 224. As UE 224 moves through radio access network 200, the network may continue to monitor uplink pilot signals sent by UE 224. When the signal strength or quality of the pilot signal measured by the neighboring cell exceeds the signal strength or quality measured by the serving cell, network 200 may handover UE 224 from the serving cell to the neighboring cell with or without notifying UE 224.

[0060] Although the synchronization signals transmitted by base stations 210, 212 and 214 / 216 may be uniform, the synchronization signals may not identify a specific cell, but may identify a region of multiple cells operating on the same frequency and / or the same timing. The use of regions in 5G networks or other next generation communication networks supports an uplink-based mobility framework and improves the efficiency of the UE and the network because the number of mobility messages that need to be exchanged between the UE and the network may be reduced.

[0061] In various implementations, the air interface in the radio access network 200 may use licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum typically provides exclusive use of a portion of the spectrum by a mobile network operator purchasing a license from a government regulator. Unlicensed spectrum provides shared use of a portion of the spectrum without the need for a government-granted license. While some technical rules generally still need to be followed to access unlicensed spectrum, generally, any operator or device can gain access. Shared spectrum may be between licensed and unlicensed spectrum, where technical rules or restrictions may be required to access the spectrum, but the spectrum may still be shared by multiple operators and / or multiple radio access technologies (RATs). For example, a licensee of a portion of licensed spectrum may provide licensed shared access (LSA) to share that spectrum with other parties, e.g., with appropriate licensee-determined conditions to gain access.

[0062] The air interface in the radio access network 200 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of various devices. For example, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP), the 5G NR specification provides multiple access for UL transmissions from UEs 222 and 224 to the base station 210, and provides multiplexing for DL ​​transmissions from the base station 210 to one or more UEs 222 and 224. In addition, for UL transmissions, the 5G NR specification provides support for discrete Fourier transform spread OFDM (DFT-s-OFDM) with CP (also known as single carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided using time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource extension multiple access (RSMA), or other suitable multiple access schemes. In addition, multiplexing of DL transmissions from base station 210 to UEs 222 and 224 may be provided using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

[0063] The air interface in the radio access network 200 may further utilize one or more duplex algorithms. Duplex refers to a point-to-point communication link in which both endpoints can communicate with each other in both directions. Full-duplex means that both endpoints can communicate with each other at the same time. Half-duplex means that only one endpoint can send information to the other endpoint at a time. Half-duplex emulation is often implemented for wireless links by utilizing time division duplex (TDD). In TDD, transmissions in different directions on a given channel are separated from each other using time division multiplexing. That is, sometimes the channel is dedicated to transmission in one direction, and at other times the channel is dedicated to transmission in another direction, where the direction can change very quickly, such as several times per time slot. In wireless links, full-duplex channels generally rely on physical isolation of the transmitter and receiver, as well as suitable interference cancellation techniques. Full-duplex emulation is often implemented for wireless links by utilizing frequency division duplex (FDD) or space division duplex (SDD). In FDD, transmissions in different directions operate on different carrier frequencies. In SDD, transmissions in different directions on a given channel are separated from each other using space division multiplexing (SDM). In other examples, full-duplex communication can be implemented within an unpaired spectrum (e.g., within a single carrier bandwidth), where transmissions in different directions occur within different sub-bands of the carrier bandwidth. This type of full-duplex communication can be referred to as sub-band full-duplex (SBFD), also known as flexible duplex.

[0064] Various aspects of the present disclosure will be described with reference to OFDM waveforms, examples of which are shown in Figure 3 Schematically illustrated in FIG. It will be appreciated by those skilled in the art that various aspects of the present disclosure may be applied to SC-FDMA waveforms in substantially the same manner as described below. That is, while some examples of the present disclosure may focus on OFDM links for clarity, it will be appreciated that the same principles may also be applied to SC-FDMA waveforms.

[0065] Reference now Figure 3 , shows an expanded view of an example subframe 302, showing an OFDM resource grid. However, as will be readily appreciated by those skilled in the art, the physical (PHY) layer transmission structure for any particular application may differ from the example described herein, depending on any number of factors. Here, time is in the horizontal direction, in units of OFDM symbols; frequency is in the vertical direction, in units of subcarriers of a carrier.

[0066] Resource grid 304 can be used to schematically represent the time-frequency resources of a given antenna port. That is, in a multiple-input multiple-output (MIMO) implementation with multiple available antenna ports, corresponding multiple resource grids 304 can be used for communication. Resource grid 304 is divided into multiple resource elements (RE) 306. RE is 1 subcarrier × 1 symbol, the smallest discrete part of the time-frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation used in a specific implementation, each RE can represent one or more information bits. In some examples, RE blocks can be referred to as physical resource blocks (PRBs) or more simply as resource blocks (RBs) 308, which contain any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB can include 12 subcarriers, the number being independent of the numerology used. In some examples, depending on the numerology, an RB can include any suitable number of consecutive OFDM symbols in the time domain. In the present disclosure, it is assumed that a single RB such as RB 308 corresponds entirely to a single communication direction (transmission or reception of a given device).

[0067] A collection of contiguous or discontinuous resource blocks may be referred to herein as a resource block group (RBG), a subband, or a bandwidth part (BWP). A collection of subbands or BWPs may span the entire bandwidth. Scheduling a scheduled entity (e.g., a UE) for downlink, uplink, or sidelink transmission typically involves scheduling one or more resource elements 306 within one or more subbands or bandwidth parts (BWPs). Thus, a UE typically uses only a subset of a resource grid 304. In some examples, an RB may be the smallest resource unit that may be allocated to a UE. Thus, the more RBs scheduled for a UE, the higher the modulation scheme selected for the air interface, and the higher the data rate for the UE. The RBs may be scheduled by a scheduling entity such as a base station (e.g., a gNB, eNB, etc.), or may be self-scheduled by a UE implementing D2D sidelink communication.

[0068] In this illustration, RB 308 is shown as occupying less than the entire bandwidth of subframe 302, with some subcarriers shown above and below RB 308. In a given implementation, subframe 302 may have a bandwidth corresponding to any number of one or more RBs 308. Additionally, in this illustration, RB 308 is shown as occupying less than the entire duration of subframe 302, although this is merely one possible example.

[0069] Each 1 ms subframe 302 may consist of one or more adjacent time slots. Figure 3In the example shown, as an illustrative example, a subframe 302 includes four time slots 310. In some examples, a time slot can be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a time slot can include 7 or 13 OFDM symbols with a nominal CP. Additional examples may include mini time slots with shorter durations (e.g., one to three OFDM symbols), sometimes referred to as shortened transmission time intervals (TTIs). In some cases, these mini time slots or shortened transmission time intervals (TTIs) may occupy resources scheduled for ongoing time slot transmissions of the same or different UEs for transmission. Any number of resource blocks can be utilized within a subframe or time slot.

[0070] An expanded view of one of the time slots 310 shows that the time slot 310 includes a control region 312 and a data region 314. In general, the control region 312 may carry a control channel and the data region 314 may carry a data channel. Of course, a time slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. Figure 3 The structure shown is merely an example, and different slot structures may be used and may include one or more of each of the control region and the data region.

[0071] Despite Figure 3 Although not shown in the figure, various REs 306 within the RB 308 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs 306 within the RB 308 may also carry pilot or reference signals. These pilot or reference signals may be provided to a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation / detection of the control and / or data channels within the RB 308.

[0072] In some examples, time slot 310 may be used for broadcast, multicast, groupcast, or unicast communications. For example, broadcast, multicast, or groupcast communications may refer to point-to-multipoint transmissions from one device (e.g., a base station, UE, or other similar device) to other devices. Here, broadcast communications are delivered to all devices, while multicast or groupcast communications are delivered to multiple intended recipient devices. Unicast communications may refer to point-to-point transmissions from one device to a single other device.

[0073] In an example of cellular communication over a cellular carrier via a Uu interface, for DL ​​transmission, a scheduling entity (e.g., a base station) may allocate one or more REs 306 (e.g., within a control region 312) to carry DL control information including one or more DL control channels (such as a physical downlink control channel (PDCCH)) to one or more scheduled entities (e.g., UEs). The PDCCH carries downlink control information (DCI), including but not limited to power control commands (e.g., one or more open-loop power control parameters and / or one or more closed-loop power control parameters), scheduling information, grants, and / or RE allocations for DL ​​and UL transmissions. The PDCCH may also carry hybrid automatic repeat request (HARQ) feedback transmissions, such as acknowledgements (ACKs) or negative acknowledgements (NACKs). HARQ is a technique well known to those of ordinary skill in the art, in which the integrity of packet transmissions may be checked at the receiving side, for example, using any suitable integrity check mechanism (such as a checksum or cyclic redundancy check (CRC)) to ensure accuracy. If the integrity of the transmission is confirmed, an ACK may be sent, and if not, a NACK may be sent. In response to the NACK, the transmitting device may send a HARQ retransmission, which may enable chase combining, incremental redundancy, and the like.

[0074] The base station may further allocate one or more REs 306 (e.g., in the control region 312 or the data region 314) to carry other DL signals, such as a demodulation reference signal (DMRS); a phase tracking reference signal (PT-RS); a channel state information (CSI) reference signal (CSI-RS); and a synchronization signal block (SSB). The SSB may be broadcast at regular intervals based on a period (e.g., 5, 10, 20, 30, 80, or 130 milliseconds). The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast control channel (PBCH). The UE may use the PSS and SSS to achieve radio frame, subframe, time slot, and symbol synchronization in the time domain, identify the center of the channel (system) bandwidth in the frequency domain, and identify the physical cell identity (PCI) of the cell.

[0075] The PBCH in the SSB may also include a master information block (MIB), which includes various system information, and parameters for decoding a system information block (SIB). The SIB may be, for example, a SystemInformationType 1 (SIB1) that may include various additional (remaining) system information. The MIB and SIB1 together provide minimum system information (SI) for initial access. Examples of system information transmitted in the MIB may include, but are not limited to, subcarrier spacing (e.g., default downlink parameters), system frame number, configuration of a PDCCH control resource set (CORESET) (e.g., PDCCH CORESET0), a cell barring indicator, a cell reselection indicator, a raster offset, and a search space for SIB1. Examples of remaining minimum system information (RMSI) transmitted in SIB1 may include, but are not limited to, a random access search space, a paging search space, downlink configuration information, and uplink configuration information. The base station may also send other system information (OSI).

[0076] Since the SI may change over time, the scheduling entity may send paging messages indicating SI changes. Therefore, the UE may periodically monitor the paging channel for these and other paging messages. If the paging message indicates that the SI has changed, the UE monitors the broadcast channel or some other designated channel to obtain the new SI.

[0077] In an UL transmission, a scheduled entity (e.g., a UE) may carry UL control information (UCI) including one or more UL control channels, such as a physical uplink control channel (PUCCH), to a scheduling entity using one or more REs 306. UCI may include multiple packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. Examples of uplink reference signals may include a sounding reference signal (SRS) and an uplink DMRS. In some examples, the UCI may include a scheduling request (SR), i.e., a request to the scheduling entity to schedule an uplink transmission. Here, in response to the SR sent on the UCI, the scheduling entity may send downlink control information (DCI) that may schedule resources for uplink packet transmissions. The UCI may also include HARQ feedback, channel state feedback (CSF), such as a CSI report, or any other suitable UCI.

[0078] In addition to control information, one or more REs 306 (e.g., within the data region 314) may be allocated for data traffic. Such data traffic may be carried on one or more traffic channels, such as, for DL ​​transmissions, a physical downlink shared channel (PDSCH); or for UL transmissions, a physical uplink shared channel (PUSCH). In some examples, one or more REs 306 within the data region 314 may be configured to carry other signals, such as one or more SIBs and DMRS.

[0079] In an example of sidelink communication on a sidelink carrier via a proximity service (ProSe) PC5 interface, a control region 312 of a time slot 310 may include a physical sidelink control channel (PSCCH) including sidelink control information (SCI) sent by an initiating (transmitting) sidelink device (e.g., a Tx V2X device or other Tx UE) toward a set of one or more other receiving sidelink devices (e.g., an Rx V2X device or some other Rx UE). A data region 314 of the time slot 310 may include a physical sidelink shared channel (PSSCH) including sidelink data traffic sent by an initiating (transmitting) sidelink device within resources reserved by the transmitting sidelink device on the sidelink carrier via the SCI. Other information may also be sent via various REs 306 within the time slot 310. For example, HARQ feedback information may be sent from a receiving sidelink device to a transmitting sidelink device in a physical sidelink feedback channel (PSFCH) within the time slot 310. Additionally, one or more reference signals may be sent within slot 310, such as a sidelink SSB, a sidelink CSI-RS, a sidelink SRS, and / or a sidelink positioning reference signal (PRS).

[0080] These physical channels are usually multiplexed and mapped to transport channels for processing at the media access control (MAC) layer. Transport channels carry information blocks called transport blocks (TBs). The transport block size (TBS), which can correspond to a number of information bits, can be a controlled parameter based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

[0081] Reference above Figure 1-Figure 3 The channels or carriers described are not necessarily all channels or carriers that may be used between a scheduling entity and a scheduled entity, and one of ordinary skill in the art will recognize that other channels or carriers may be used in addition to those shown, such as other traffic, control, and feedback channels.

[0082] Figure 4AAn example 400 of various downlink channels within a subframe of a frame including channels used for initial access and synchronization is shown. Figure 4A As shown, the physical downlink control channel (PDCCH) 402 is transmitted in at least two symbols (e.g., symbol 0 and symbol 1) and can carry DCI in at least one control channel element (CCE), each CCE includes nine RE groups, and each RE group (REG) includes four consecutive REs in one OFDM symbol. In addition, Figure 4A An exemplary synchronization signal block (SSB) 404 that may be periodically transmitted by a base station or gNB is shown. The SSB 404 carries synchronization signals PSS 406 and SSS 408 and a broadcast channel (PBCH) 410. In this example, the SSB 404 includes one PSS symbol (as shown in symbol 2), one SSS symbol (as shown in symbol 4), and two PBCH symbols (as shown in symbols 3 and 5). The PSS and SSS combination may be used to identify a physical cell identity. The UE uses the PSS to determine subframe / symbol timing and physical layer identity. The SSS is used by the UE to determine the physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE may determine the physical cell identifier (PCI). In addition, based on the PCI, the UE may determine the location of the DMRS described above. The physical broadcast channel (PBCH) carrying the master information block (MIB) is logically grouped with the PSS and SSS to form a synchronization signal; i.e., the SSB 404. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN).

[0083] Figure 4B is a diagram illustrating various broadcast information 450 related to initial cell access according to some examples. The broadcast information 450 may be sent by a RAN node (e.g., a base station such as an eNB or gNB) on resources (e.g., time-frequency resources) allocated for transmission of the broadcast information 450 in a cell. The broadcast information 450 includes Figure 4A454. Note that the PBCH in the SSB 404 includes a MIB that carries various system information (SI), including, for example, a cell barring indication, a subcarrier spacing, a system frame number, and scheduling information for CORESET0 452. For example, the PBCH in the SSB 404 may include scheduling information indicating the time-frequency resources allocated to CORESET0 452. In some examples, CORESET 0 452 may be sent within the first four symbols of the time slot (e.g., within the control region). In addition, CORESET0 452 carries a PDCCH with DCI, including scheduling information for scheduling SIB1 454. SIB1 454 is carried within a physical downlink shared channel (PDSCH) within the data region of the time slot. In addition, SIB1 454 may be referred to as RMSI and includes, for example, a set of radio resource parameters that provide network identification and configuration. For example, the set of radio resource parameters may include a bandwidth (e.g., the number of BWPs) over which a UE can communicate with a base station.

[0084] The MIB in the PBCH may include system information (SI) and parameters for decoding the SIB (e.g., SIB1). Examples of SI transmitted in the MIB may include, but are not limited to, subcarrier spacing, system frame number, configuration of a PDCCH control resource set (CORESET) (e.g., PDCCH CORESET0), and search space of SIB1. Examples of SI transmitted in SIB1 may include, but are not limited to, random access search space, downlink configuration information, and uplink configuration information. MIB and SIB1 together provide minimum SI for initial access.

[0085] Below is a brief summary of an example of an initial access procedure for a UE using the above information. As described above, the BS may send synchronization signals (e.g., including PSS and SSS) in the network to enable the UE to synchronize with the BS, as well as send SI to facilitate initial network access. A UE attempting to access the RAN may perform an initial cell search by detecting the PSS of the BS from the RAN (e.g., the PSS of a cell of the BS). As described above, the PSS may enable the UE to synchronize with the periodic timing of the BS and may indicate a physical layer identification value assigned to the cell. The UE may also receive the SSS from the BS, enabling the UE to synchronize with the cell at the radio frame level. The SSS may also provide a cell identification value, which the UE may combine with the physical layer identification value to determine the PCI of the cell.

[0086] Wireless communication networks such as NR networks may support carrier aggregation in a multi-cell transmission environment, where, for example, different base stations and / or different transmit and receive points (TRPs) may transmit on different component carriers. In some aspects, the term component carrier may refer to a carrier frequency (or frequency band) used for communications within a cell. In some examples, different TRPs may be associated with a single serving cell (e.g., a single base station). In some examples, different TRPs may be associated with different serving cells (e.g., different base stations may employ different TRPs).

[0087] exist Figure 5 An example of a multi-cell transmission environment 500 is shown in FIG. The multi-cell transmission environment 500 includes a primary serving cell (PCell) 502 and one or more secondary serving cells (SCells) 506a, 506b, 506c, and 506d. PCell 502 may be referred to as an anchor cell that provides a radio resource control (RRC) connection to a UE (e.g., UE 510). In some examples, the PCell and one or more SCells may be co-located. For example, a TRP for a PCell and a TRP for an SCell may be installed in the same location.

[0088] When carrier aggregation is used in the multi-cell transmission environment 500, one or more of the SCells 506a-506d may be activated or added to the PCell 502 to form a serving cell serving the UE 510. In this case, each of these serving cells corresponds to a component carrier (CC). The CC of the PCell 502 may be referred to as a primary CC, and the CC of the SCell (e.g., SCells 506a-506d) may be referred to as a secondary CC. Each of the PCell 502 and the SCells 506a-506d may be served by a corresponding base station or scheduling entity, such as Figure 1 and 2 As described in Figure 5 In the example of FIG. 5 , PCell 502 is served by base station 504, and SCells 506a-506c are each served by a corresponding base station 508a-508c. In addition, SCell 506d is co-located with PCell 502. For example, base station 504 may include multiple TRPs, each TRP supporting a different carrier. The coverage of PCell 502 and the coverage of SCell 506d may be different, such as Figure 5 For example, component carriers in different frequency bands may experience different path losses, thereby providing different coverage areas.

[0089] In some examples, PCell 502 may utilize a first radio access technology (RAT), such as LTE, and one or more SCells 506 may utilize a second RAT, such as NR. In this case, the multi-cell transmission environment may be referred to as a multi-RAT-dual connection (MR-DC) environment. In some examples, PCell 502 may be a low-band cell and SCell 506 may be a high-band cell. Low-band (LB) cells use CCs in a frequency band lower than high-band cells. For example, high-band cells may use millimeter wave CCs, and low-band cells may use CCs in a frequency band lower than millimeter waves (e.g., sub-6 GHz bands). Typically, cells using millimeter wave CCs can provide a larger bandwidth than cells using low-band CCs. In addition, when using a frequency carrier (e.g., millimeter wave) higher than 6 GHz, beamforming may be used to send and receive signals.

[0090] In some scenarios, the base station 504 may add / remove one or more SCells 506a-506d to / from the CC set. For example, as the UE 510 moves or as channel conditions or data requirements change over time, the UE 510 may be better served by different SCells. Therefore, the base station 504 may choose to use different SCells for the CC set, for example, to improve the reliability of the connection to the UE 510 and / or to increase the data rate of such a connection.

[0091] Additionally, UE 510 may be handed over from PCell 502 to another PCell. For example, as UE 510 moves or as channel conditions or data requirements change over time, UE 510 may be better served by a different PCell (eg, a PCell served by a different base station).

[0092] To enable UEs to switch between cells (inter-cell mobility), a base station may collect measurement reports from the UEs it serves. These measurement reports may be based on UE measurements of signal quality (e.g., signal strength) of signals received from nearby cells. Based on these signal quality measurements, the base station may identify the best candidate cell for the UE.

[0093] For certain types of mobility measurements, the UE may use a timing reference (e.g., of a cell) to measure signals from a cell. For example, in NR, protocol layer 3 (hereinafter referred to as L3) mobility measurements may be based on an SSB measurement timing configuration (SMTC). In some examples, the SMTC may specify a time window and an SSB position and time slot within the time window that the UE may use to measure the SSB of a neighboring cell for mobility purposes.

[0094] In some examples, the SMTC can be based on the timing reference of the cell. For example, in NR, the following timing references can be used for changes in the primary cell (PCell), changes in the primary secondary cell (PSCell), or addition of a secondary cell (SCell). For NR PCell changes, the SMTC can be based on the timing reference of the source PCell. For NR PSCell changes, the SMTC can be based on the timing reference of the source PSCell. For NR SCell additions, the SMTC can be based on the timing of the SpCell of the associated cell group. SpCell refers to a PCell (e.g., a Pcell of an MCG) or a PSCell (e.g., of an SCG).

[0095] In some examples, inter-cell mobility in NR involves operations at different protocol layers. Protocol layer 1 inter-cell mobility may be referred to herein as L1 inter-cell mobility. Protocol layer 2 inter-cell mobility may be referred to herein as L2 inter-cell mobility. In some examples, L1 and L2 inter-cell mobility may involve two different modes of operation.

[0096] In the first operation mode (mode 1), the serving cell is configured with multiple TRPs. These TRPs may be located at different locations. In addition, different TRPs may have different PCIs. For a given TRP, the corresponding PCI may be carried by the SSB sent by the TRP, as described above.

[0097] Figure 6 An example of a wireless communication system 600 is shown in which a UE 602 is served by a set of TRPs (TRP 604a, TRP 604b, TRP 604c, and TRP 604d) of a BS 606 associated with a serving cell. In some scenarios, other cells (not shown) may be in the vicinity of the UE 602. In some examples, the UE 602 may correspond to Figure 1 , Figure 5 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 In some examples, each of TRP 604a, TRP 604b, TRP 604c, and TRP 604d may be Figure 1 , Figure 5 , Figure 7 , Figure 8 , Fig. 9 and Fig.13 The TRP of any BS or scheduling entity shown in any of the .

[0098] Each of TRP 604a, TRP 604b, TRP 604c, and TRP 604d may use a unique (e.g., locally unique) PCI. For example, TRP 604a may use a first PCI, TRP 604b may use a second PCI, TRP 604c may use a third PCI, and TRP 604d may use a fourth PCI. These PCIs enable UE 602 to uniquely identify each corresponding TRP. In some examples, a cell served by a TRP may be referred to as a sub-cell of a serving cell (e.g., a serving cell of BS 606).

[0099] At a given point in time, a UE may be served by a subset of all sub-cells of a serving cell (e.g., a cell of a TRP that has been selected to serve the UE). In addition, the serving cell may change this subset from time to time.

[0100] For example, in Figure 6 , BS 606 serving UE 602 may have selected four TRPs (TRP 604a, TRP 604b, TRP 604c, and TRP 604d) near UE 602 as candidate subcells for UE 602. In addition, BS 606 may have configured UE 602 to be served by two TRPs (TRP 604b and TRP 604c) represented by dashed lines 608a and 608b. Therefore, in this case, UE 602 can be served by a first subcell associated with TRP 604b and a second subcell associated with TRP 604c.

[0101] In some examples, the decision of the serving cell to change the serving subset of the UE may be based on measurements made by the UE. For example, the UE may be configured to measure an L1 metric (e.g., for each serving TRP, for each candidate TRP, or for some other TRP group). The metric may include, for example, one or more of a reference signal received power (RSRP), a signal to interference plus noise ratio (SINR), or a reference signal received quality (RSRQ).

[0102] Upon determining a change in the guaranteed subset (e.g., if the measured metrics have changed significantly relative to one or more TRPs), the serving cell may send an indication of the change to the UE (e.g., identifying any PCIs that have been added or removed from the subset). In some examples, the serving cell (e.g., gNB) may send the indication via downlink control information (DCI), via a media access control-control element (MAC-CE), via a radio resource control (RRC) message, via some other type of signaling technique, or via a combination of two or more of these signaling techniques.

[0103] exist Figure 6In the example of , BS 606 will send an indication of the PCI of the subset of TRPs to UE 602. For example, BS 606 may send an indication of the PCI of TRP 604b and the PCI of TRP 604c to UE 602.

[0104] In the second operation mode (mode 2), the UE is configured with a set of serving cells (e.g., a set of cell candidates) (e.g., by a primary serving cell). Here, different serving cells have different PCIs (e.g., one PCI for each serving cell). For a given serving cell, the PCI may be carried by the SSB sent by the serving cell.

[0105] Figure 7 An example of a wireless communication system 700 is shown in which a UE 702 is served by a set of serving cells represented by BS 704a, BS 704b, BS 704c, BS 704d, and BS 704e. In some scenarios, other cells (not shown) may be near the UE 702. In some examples, the UE 702 may correspond to Figure 1 , Figure 5 , Figure 6 , Figure 8 , Fig. 9 and Fig.10 In some examples, each of BS 704a, BS 704b, BS 704c, BS 704d, and BS 704e may correspond to Figure 1 , Figure 5 , Figure 6 , Figure 8 , Fig. 9 and Fig.13 Any BS or scheduling entity shown in any one of .

[0106] Each of BS 704a, BS 704b, BS 704c, BS 704d, and BS 704e may use a unique (e.g., locally unique) PCI. For example, BS 704a may use a first PCI, BS 704b may use a second PCI, BS 704c may use a third PCI, BS 704d may use a fourth PCI, and BS 704e may use a fifth PCI. These PCIs enable the UE to uniquely identify each corresponding cell.

[0107] At a given point in time, a UE may be served by a subset of a serving cell group. This subset may change from time to time. For example, one of the serving cells (e.g., a primary serving cell such as a gNB) may select the subset based on L1 reports (e.g., L1 RSRP, SINR, RSRQ) from the UE. In some examples, the UE may send these reports to an anchor serving cell in a selected set of serving cells or a serving cell group. Upon determining that a change in the subset is warranted (e.g., if a measured metric has changed significantly relative to one or more measured cells), the primary serving cell may send an indication of the change to the UE (e.g., identifying a PCI that has been added or removed from the subset), as described above.

[0108] For example, in Figure 7 , BS 704a serving UE 702 (e.g., a primary cell or anchor cell) may have selected five BSs (BS 704a, BS 704b, BS 704c, BS 704d, and BS 704e) in the vicinity of UE 702 as candidate cells for UE 702. In addition, BS 704a may have configured UE 702 to be served by three BSs (BS 704a, BS 704b, BS 704c), as shown by dashed lines 706a, dashed lines 706b, and dashed lines 706c. BS 704a will therefore send an indication of the PCIs of the subset of cells to UE 702. For example, BS 704a may send an indication of the PCI of BS 704a, the PCI of BS 704b, and the PCI of BS 704c to UE 702.

[0109] Therefore, in Figure 6 and Figure 7 In the scenario of , each of BS 606 and BS 704a can perform mobility operations to try to ensure that the served UE is being served by the best cell. For example, over time, BS 606 and BS 704a can change the set of selected candidate cells / TRPs and / or serving cells / TRPs for a particular UE. Such changes can be triggered by, for example, movement of the UE, changes in channel conditions, changes in data throughput requirements, or some other type of operational changes.

[0110] The present disclosure relates in various aspects to mobility operations in a multi-cell environment. For example, a UE served by multiple cells, each with its own unique PCI, may select one of these PCIs as a timing reference for mobility measurements.

[0111] In some examples, the UE may perform L3 mobility measurements in a scenario where the UE is served by multiple cells and / or TRPs. In this case, the timing reference for the L3 mobility measurement may be selected from a set of cells and / or TRPs near the UE. This set of cells and / or TRPs may be referred to herein as a candidate cell / TRP set. In addition, the PCI associated with the candidate cell / TRP set may be referred to herein as a candidate PCI set. Below are two examples of selecting a timing reference for L3 mobility measurements.

[0112] In a first example, a timing reference for L3 mobility measurements in L1 and / or L2 mobility (e.g., SSB Measurement Timing Configuration (SMTC)) can be based on a timing reference of one PCI in a subset of PCIs that has been selected to serve the UE. In some examples, the subset of PCIs is a subset of a set of candidate PCIs for the UE. If there is only one PCI in the subset, the timing reference for the SMTC can be based on the downlink receive timing of that PCI.

[0113] If there are multiple PCIs in the subset, the timing reference can be based on one of the PCIs in the subset. Below are two options for determining which PCI of the subset to use. Other techniques for determining which PCI of the subset to use can be used in other examples.

[0114] In the first option, the UE determines the PCI to use based on a rule. The rule may take different forms in different implementations.

[0115] In some examples, the rule may be a predefined rule (e.g., an implicit rule). In some examples, the rule may be specified by a communication standard such as a 3GPP technical specification. In some examples, the rule may be programmed into the wireless communication during initial deployment in the network.

[0116] In some examples, the rule may be a defined rule (e.g., a rule received by the UE from a base station). In some examples, the rule may specify that the UE use the PCI with the lowest PCI value in the PCI subset selected to serve the UE. In some examples, the rule may specify that the UE use the PCI with the highest PCI value in the PCI subset selected to serve the UE. Other rules may be used in other examples.

[0117] In a second option, the UE determines the PCI to use based on explicit signaling. For example, a base station (e.g., a gNB) may send an indication to the UE of the PCI that the UE will use to determine the timing reference. The base station may send the indication via downlink control information (DCI), via a media access control-control element (MAC-CE), via radio resource control (RRC), via some other type of signaling technique, or by combining two or more of these signaling techniques.

[0118] Figure 8 8 is a signaling diagram 800 illustrating a signaling example for a first example in a wireless communication system including a UE 802 and a base station (BS) 804 serving several cells and / or TRPs (e.g., cell / TRP 806 to cell / TRP 808). As discussed herein, each cell / TRP may be associated with a unique PCI. In some examples, the UE 802 may correspond to Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 and Fig.10 In some examples, BS 804 may correspond to any UE or scheduled entity shown in any of Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 and Fig.13 Any base station or scheduling entity shown in any of the .

[0119] exist Figure 8 At 810, BS 804 selects a candidate PCI set for UE 802. For example, based on a measurement report received from UE 802, BS 804 may identify a set of cells or TRPs near UE 802. At 812, BS 804 may send an indication of the candidate PCI set to UE 802.

[0120] At 814, BS 804 selects a subset of the set of candidate PCIs to serve UE 802. For example, based on measurement reports received from UE 802, BS 804 may identify a subset of candidate PCIs that will best serve UE 802 at this point in time. At 816, BS 804 may send an indication of the PCI subset to UE 802.

[0121] At optional 818, BS 804 may select a timing reference to be used for SSB measurements by UE 802. For example, BS 804 may determine that UE 802 should use an anchor cell of UE 802 as a timing reference. At 820, BS 804 may send an indication of the selected timing reference (e.g., the PCI of the anchor cell) to UE 802.

[0122] At 822, if there is only one PCI in the subset, the UE 802 may select the PCI for determining a timing reference to be used for SSB measurements by the UE 802. Alternatively, at 824, if there are multiple PCIs in the subset, the UE 802 may select a PCI from the subset using a rule (e.g., highest / lowest PCI value) or received signaling (e.g., the PCI signaled at 820).

[0123] At 826, UE 802 determines the timing of receiving downlink (DL) signals 828 associated with the selected PCI. At 830, UE 802 uses the timing determined at 826 as a timing reference for the SMTC to measure SSBs 832 sent by one or more cells / TRPs (e.g., from a set of candidate cells / TRPs associated with a set of candidate PCIs).

[0124] At 834 and 836, UE 802 and BS 804 perform mobility operations. For example, UE 802 may generate a measurement report based on the SSB measurement at 830 and send the measurement report to BS 804. Based on the measurement report, BS 804 may choose to change one or more of the candidate cell / TRP set of UE 802, the serving cell / TRP subset of UE 802, the anchor cell of UE 802, or perform some other mobility operation (e.g., handover).

[0125] In the second example mentioned above, the timing reference for layer 3 mobility measurements can be selected from a set of PCIs (e.g., candidate PCIs) assigned to the UE. For example, the timing reference can be selected based on the timing reference of a PCI in the candidate PCI set, regardless of which PCIs have been (or which PCI has been) selected as the serving PCI. If there is a PCI in the PCI set (e.g., an anchor PCI), that PCI is selected. In some examples, the anchor PCI can be dedicated to broadcast, control and / or measurement report signaling. In some examples, the main data service can be served by other PCIs selected as a subset of the PCIs serving the UE.

[0126] If there are multiple PCIs in a PCI set, the timing reference can be based on one PCI in the PCI set. Below are two options for determining which PCI in a PCI set to use. Other techniques for determining which PCI in a PCI set to use can be used in other examples.

[0127] In the first option, the UE determines the PCI to use based on a rule. The rule may take different forms in different implementations.

[0128] In some examples, the rule may be a predefined rule (e.g., an implicit rule). In some examples, the rule may be specified by a communication standard such as a 3GPP technical specification. In some examples, the rule may be programmed into the wireless communication during initial deployment in the network.

[0129] In some examples, the rule may be a defined rule (e.g., a rule received by the UE from a base station). In some examples, the rule may specify that the UE use the PCI with the lowest PCI value in the PCI subset selected to serve the UE. In some examples, the rule may specify that the UE use the PCI with the highest PCI value in the PCI subset selected to serve the UE. Other rules may be used in other examples.

[0130] In a second option, the UE determines the PCI to use based on explicit signaling. For example, a base station (e.g., a gNB) may send an indication to the UE of the PCI that the UE will use to determine the timing reference. The base station may send the indication via downlink control information (DCI), via a media access control-control element (MAC-CE), via radio resource control (RRC), via some other type of signaling technique, or by combining two or more of these signaling techniques.

[0131] Fig. 9 9 is a signaling diagram 900 illustrating a first example signaling example in a wireless communication system including a UE 902 and a base station (BS) 904 serving several cells and / or TRPs (e.g., cell / TRP 906 to cell / TRP 908). As discussed herein, each cell / TRP may be associated with a unique PCI. In some examples, the UE 902 may correspond to Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig.10 In some examples, BS 904 may correspond to any UE or scheduled entity shown in any of the examples. Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig.13 Any base station or scheduling entity shown in any of the .

[0132] exist Fig. 9 At 910, BS 904 selects a candidate PCI set for UE 902. For example, based on a measurement report received from UE 902, BS 904 may identify a set of cells or TRPs near UE 902. At 912, BS 904 may send an indication of the candidate PCI set to UE 902.

[0133] At 914, BS 904 selects a subset of the candidate PCI set to serve UE 902. For example, based on measurement reports received from UE 902, BS 904 may identify a subset of candidate PCIs that will best serve UE 902 at this point in time. At 916, BS 904 may send an indication of the PCI subset to UE 902.

[0134] At optional 918, BS 904 may select a timing reference to be used for SSB measurements by UE 902. For example, BS 904 may determine that UE 902 should use an anchor cell of UE 902 as a timing reference. At 920, BS 904 may send an indication of the selected timing reference (e.g., the PCI of the anchor cell) to UE 902.

[0135] At 922, the UE 902 selects a specific PCI (e.g., a designated PCI) from the set of candidate PCIs for determining a timing reference to be used for SSB measurements by the UE 902. For example, the UE 902 may select a PCI associated with an anchor cell for the UE 902. Alternatively, at 924, the UE 902 may select a PCI from the set of candidate PCIs using a rule (e.g., a highest / lowest PCI value) or received signaling (e.g., the PCI signaled at 920).

[0136] At 926, the UE 902 determines the timing of the received downlink (DL) signal 928 associated with the selected PCI. At 930, the UE 902 uses the timing determined at 926 as a timing reference for the SMTC to measure SSBs 932 transmitted by one or more cells / TRPs (e.g., from a set of candidate cells / TRPs).

[0137] At 934 and 936, UE 902 and BS 904 perform mobility operations. For example, UE 902 may generate a measurement report based on the SSB measurement at 930 and send the measurement report to BS 904. Based on the measurement report, BS 904 may choose to change one or more of the candidate cell / TRP set of UE 902, the serving cell / TRP subset of UE 902, the anchor cell of UE 902, or perform some other mobility operations (e.g., handover).

[0138] Fig.10 1 is a block diagram illustrating an example of a hardware implementation of a UE 1000 using a processing system 1014. For example, the UE 1000 may be a device configured to wirelessly communicate with a base station, such as Figure 1-Figure 9 In some implementations, the UE 1000 may correspond to Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 Any UE or scheduled entity shown in any one of .

[0139] According to various aspects of the present disclosure, the processing system 1014 may be utilized to implement any combination of elements or any part of elements. The processing system 1014 may include one or more processors 1004. Examples of the processor 1004 include a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gated logic, a discrete hardware circuit, and other suitable hardware that are configured to perform the various functions described in the present disclosure. In various examples, the UE 1000 may be configured to perform any one or more functions described herein. That is, the processor 1004 as used in the UE 1000 may be used to implement any one or more of the processes and procedures described herein.

[0140] The processor 1004 may be implemented by a baseband or modem chip in some cases, and in other implementations, the processor 1004 may include multiple devices that are distinct and different from the baseband or modem chip (e.g., in such a scenario, they may work together to implement the examples discussed herein). And as described above, various hardware arrangements and components other than the baseband modem processor may be used in the implementation, including RF chains, power amplifiers, modulators, buffers, interleavers, adders / summers, etc.

[0141] In this example, the processing system 1014 can be implemented with a bus architecture, generally represented by bus 1002. Bus 1002 may include any number of interconnecting buses and bridges, depending on the specific application and overall design constraints of the processing system 1014. Bus 1002 communicatively couples various circuits including one or more processors (generally represented by processor 1004), memory 1005, and computer readable media (generally represented by computer readable media 1006). Bus 1002 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and will not be described further. Bus interface 1008 provides an interface between bus 1002 and transceiver 1010 and between bus 1002 and interface 1030. Transceiver 1010 provides a communication interface or component for communicating with various other devices over a wireless transmission medium. The interface 1030 provides a communication interface or component for communicating with various other devices and equipment (e.g., other devices contained in the same device as the UE or other external devices) through an internal bus such as an Ethernet cable or an external transmission medium. Depending on the nature of the device, the interface 1030 may include a user interface (e.g., a keypad, a display, a speaker, a microphone, a joystick). Of course, such a user interface is optional and may be omitted in some examples, such as IoT devices.

[0142] The processor 1004 is responsible for managing the bus 1002 and general processing, including the execution of software stored on the computer-readable medium 1006. The software, when executed by the processor 1004, causes the processing system 1014 to perform the various functions described below for any particular device. The computer-readable medium 1006 and the memory 1005 can also be used to store data that is manipulated by the processor 1004 when executing the software. For example, the memory 1005 can store PCI information 1015 used by the processor 1004 for PCI-related operations described herein.

[0143] One or more processors 1004 in the processing system can execute software. Software should be broadly interpreted to mean instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium 1006.

[0144] Computer readable medium 1006 may be a non-transitory computer readable medium. Non-transitory computer readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact disks (CDs) or digital versatile disks (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM)), registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. Computer readable medium 1006 may reside in processing system 1014, external to processing system 1014, or distributed among multiple entities including processing system 1014. Computer readable medium 1006 may be embodied in a computer program product. For example, a computer program product may include a computer readable medium in packaging material. Those skilled in the art will recognize how to best implement the functions described throughout this disclosure based on the specific application and the overall design constraints imposed on the entire system.

[0145] UE 1000 may be configured to perform any one or more operations described herein (e.g., as described above in conjunction with Figure 1-Figure 9 As described and in combination with Figure 11-Figure 12 In some aspects of the present disclosure, the processor 1004 as used in the UE 1000 may include circuits configured for various functions.

[0146] The processor 1004 may include a communication and processing circuit 1041. The communication and processing circuit 1041 may be configured to communicate with a base station such as a gNB. The communication and processing circuit 1041 may include one or more hardware components that provide a physical structure for performing various processing related to wireless communication (e.g., signal reception and / or signal transmission) as described herein. The communication and processing circuit 1041 may also include one or more hardware components that provide a physical structure for performing various processing related to signal processing (e.g., processing received signals and / or processing signals for transmission) as described herein. In some examples, the communication and processing circuit 1041 may include two or more transmit / receive chains. The communication and processing circuit 1041 may also be configured to execute communication and processing software 1051 included on the computer-readable medium 1006 to implement one or more functions described herein.

[0147] In some implementations where the communication involves receiving information, the communication and processing circuitry 1041 may obtain information from a component of the UE 1000 (e.g., from a transceiver 1010 that receives information via radio frequency signaling or some other type of signaling suitable for an applicable communication medium), process (e.g., decode) the information, and output the processed information. For example, the communication and processing circuitry 1041 may output the information to another component of the processor 1004, the memory 1005, or the bus interface 1008. In some examples, the communication and processing circuitry 1041 may receive one or more signals, messages, other information, or any combination thereof. In some examples, the communication and processing circuitry 1041 may receive information via one or more channels. In some examples, the communication and processing circuitry 1041 may include the functionality of a component for receiving. In some examples, the communication and processing circuitry 1041 may include the functionality of a component for decoding.

[0148] In some implementations where communication involves sending (e.g., transmitting) information, the communication and processing circuitry 1041 may obtain information (e.g., from the processor 1004, the memory 1005, or another component of the bus interface 1008), process (e.g., encode) the information, and output the processed information. For example, the communication and processing circuitry 1041 may output the information to the transceiver 1010 (e.g., sending the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium). In some examples, the communication and processing circuitry 1041 may send one or more of a signal, a message, other information, or any combination thereof. In some examples, the communication and processing circuitry 1041 may send information via one or more channels. In some examples, the communication and processing circuitry 1041 may include functionality of a component for sending (e.g., a component for transmitting). In some examples, the communication and processing circuitry 1041 may include functionality of a component for encoding.

[0149] Processor 1004 may include PCI selection circuit 1042 configured to perform PCI selection related operations as discussed herein (e.g., as described above in conjunction with Figure 8 and Fig. 9 PCI selection circuit 1042 may include functionality for receiving an indication of a candidate PCI set (e.g., as described in Figure 8 812 and / or 816, and / or Fig. 9 912 and / or 916, and / or Fig.11 PCI selection circuit 1042 may include functionality for selecting a component of PCI (e.g., Figure 8 822 and / or 824, and / or Fig. 9 922 and / or 924, and / or Fig.11The PCI selection circuit 1042 may also be configured to execute PCI selection software 1052 included on the computer-readable medium 1006 to implement one or more functions described herein.

[0150] Processor 1004 may include mobility circuitry 1043 configured to perform mobility-related operations as discussed herein (e.g., as described above in conjunction with Figure 8 and Fig. 9 The mobility circuit 1043 may include functionality of a component for determining a timing reference (e.g., as described in Figure 8 826, and / or Fig. 9 926, and / or Fig.11 The mobility circuit 1043 may include the functionality of a component for performing SSB measurements (e.g., Figure 8 830, and / or Fig. 9 930, and / or Fig.11 The mobility circuit 1043 may include the functionality of a component for generating a measurement report (e.g., in Figure 8 834, and / or Fig. 9 934, and / or Fig.11 The mobility circuit 1043 may include the functionality of a component for sending a measurement report (e.g., in Figure 8 834, and / or Fig. 9 934, and / or Fig.11 The mobility circuit 1043 may also be configured to execute mobility software 1053 included on the computer-readable medium 1006 to implement one or more functions described herein.

[0151] Fig.11 1 is a flow chart illustrating an example wireless communication method 1100 according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for implementation of all examples. In some examples, the method 1100 may be composed of Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 In some examples, method 1100 may be performed by any UE or scheduled entity shown in any of the above. Fig.10The method 1100 may be performed by the processing system 1014. In some examples, the method 1100 may be performed by any suitable device or component for performing the functions or algorithms described below.

[0152] At block 1102, the UE may receive a first indication of a candidate physical cell identifier (PCI) of the user equipment from a base station. For example, the communication and processing circuit 1041 and the transceiver 1010, as described above, may be combined Fig.10 As shown and described, a message may be received from a base station identifying the PCI of cells and / or TRPs that have been identified as candidates for serving a UE.

[0153] In some examples, a subset of the set of candidate PCIs may include at least one PCI selected to serve the UE. In some examples, the subset includes only the first PCI.

[0154] In some examples, the first transmit / receive point of the first service cell of the user equipment can be identified by the second PCI in the candidate PCI set, and the second transmit / receive point of the first service cell can be identified by the third PCI in the candidate PCI set. In some examples, the first service cell of the UE can be identified by the second PCI in the candidate PCI set, and the second service cell of the UE can be identified by the third PCI in the candidate PCI set.

[0155] In some examples, the candidate PCI set may include multiple PCIs for at least one serving cell of the UE. In some examples, the first PCI may include an anchor PCI for the UE. In some examples, the anchor PCI may be associated with at least one of a broadcast service, a control service, a measurement report service, or any combination thereof. In some examples, one or more PCIs of the multiple candidate PCIs may be associated with a data service.

[0156] In some examples, the candidate PCI set may be associated with a plurality of transmit reception points (TRPs) of a serving cell of the UE. In some examples, the serving cell may include a primary cell, a secondary cell, or a primary and secondary cell.

[0157] In some examples, the candidate PCI set may be associated with multiple serving cells of the UE. In some examples, the serving cell may include a primary cell, a secondary cell, or at least one of a primary and secondary cell.

[0158] At block 1104, the UE may select a first PCI from the set of candidate PCIs. Fig.10The PCI selection circuit 1042 shown and described may select one of the PCIs of the candidate PCI set or one of the PCIs of a subset of the candidate PCI set. In some examples, if the subset of the candidate PCI set specified for the UE includes only one PCI, the PCI selection circuit 1042 may select that PCI. As another example, if the subset includes multiple PCIs, the PCI selection circuit 1042 may select one of those PCIs (e.g., based on an implicit rule or based on explicit signaling from the base station).

[0159] At block 1106, the UE may determine a timing reference for synchronization signal block (SSB) measurement from the downlink reception timing associated with the first PCI. For example, the mobility circuit 1043 together with the communication and processing circuit 1041 and the transceiver 1010, as described above in conjunction with Fig.10 As shown and described, the downlink reception timing associated with the first PCI may be measured. In addition, the mobility circuit 1043 may choose to use the measured downlink reception timing as a timing reference for the SMTC.

[0160] At block 1108, the UE may perform SSB measurements using the timing reference. For example, the mobility circuitry 1043 in conjunction with the communication and processing circuitry 1041 and the transceiver 1010 may measure L1 metrics of SSB transmissions from neighboring cells / TRPs using the SMTC based on the timing reference determined at block 1106, as discussed herein.

[0161] In some examples, the SSB measurements use an SSB measurement timing configuration (SMTC) that can be based on a timing reference. In some examples, the SSB measurements can include protocol layer 3 measurements.

[0162] At optional block 1110, the UE may generate a measurement report based on the SSB measurement.For example, the mobility circuitry 1043 may generate a report identifying the measured PCI and its associated L1 metric.

[0163] At optional block 1112, the UE may send a measurement report to the base station. For example, the mobility circuit 1043 together with the communication and processing circuit 1041 and the transceiver 1010 may send the measurement report to a serving cell (e.g., a serving cell if there is only one serving cell, or a primary serving cell if there are multiple serving cells).

[0164] In some examples, the processing may also include receiving a second indication of a subset of the candidate PCI set from the base station. In some examples, wherein selecting the first PCI from the candidate PCI set may include selecting the first PCI from the subset. In some examples, the subset includes only the first PCI.

[0165] In some examples, the processing may also include receiving a physical cell identifier (PCI) selection indication from a base station, wherein selecting a first PCI from a set of candidate PCIs may include selecting the first PCI using the PCI selection indication. In some examples, the PCI selection indication specifies that the UE will select the first PCI using a predefined rule. In some examples, the processing may also include receiving a second indication of a subset of the candidate PCI set from the base station. In some examples, the method may also include selecting the first PCI from the subset using a predefined rule. In some examples, the candidate PCI set may include multiple PCIs for at least one serving cell of the UE, and the method may also include selecting a timing reference from the multiple candidate PCIs using a predefined rule. In some examples, the predefined rule specifies that the UE is to select a PCI associated with the lowest PCI value. In some examples, the predefined rule specifies that the UE is to select a PCI associated with the highest PCI value. In some examples, the PCI selection indication specifies that the UE uses a specific PCI (e.g., a specific PCI) identified by the base station.

[0166] In some examples, processing may also include receiving an indication of a specific PCI from a base station. In some examples, receiving an indication of a specific PCI may include receiving an indication of a specific PCI via a downlink control information (DCI), a media access control-control element (MAC-CE), or a radio resource control (RRC) message.

[0167] Fig.12 1 is a flow chart illustrating an example wireless communication method 1200 according to some aspects. In some examples, the method 1200 may be combined with Fig.11 The method 1100 is implemented (for example, except Fig.11 As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present invention, and some of the illustrated features may not be required for implementation of all examples. In some examples, method 1200 may be performed by Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10 In some examples, method 1200 may be performed by any UE or scheduled entity shown in any of the above. Fig.10 The method 1200 is performed by the processing system 1014. In some examples, the method 1200 can be performed by any suitable device or component for performing the functions or algorithms described below.

[0168] At block 1202, the UE may receive a PCI selection indication from a base station. For example, the communication and processing circuit 1041 and the transceiver 1010, as described above, may be combined Fig.10 As shown and described, the DCI including the indication may be received via the PDCCH or the MAC-CE or RRC message including the indication may be received via the PDSCH.

[0169] At block 1204, the UE may use the PCI selection indication to select the first PCI. For example, if the PCI selection indication indicates that the UE will use the rules for PCI selection, then the above combined Fig.10 The PCI selection circuit 1042 shown and described may select that PCI based on a rule (e.g., selecting the highest or lowest PCI value). As another example, if the PCI selection indication indicates that the UE will use explicit signaling for PCI selection, the PCI selection circuit 1042 may select the PCI based on an indication of the PCI to be used received from the base station.

[0170] Fig.13 13 is a conceptual diagram illustrating an example of a hardware implementation of a base station (BS) 1300 employing a processing system 1314. In some implementations, the BS 1300 may correspond to Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 Any BS (e.g., gNB) or scheduling entity shown in.

[0171] According to various aspects of the present disclosure, the processing system 1314 may be used to implement an element or any portion of an element or any combination of elements. The processing system may include one or more processors 1304. The processing system 1314 may be substantially similar to Fig.10 1300, including a bus interface 1308, a bus 1302, a memory 1305, a processor 1304, and a computer-readable medium 1306. The memory 1305 can store PCI information 1315 (e.g., PCI of a candidate unit and / or a subset of a candidate unit) used by the processor 1304 in cooperation with the transceiver 1310 for mobility operations. In addition, the BS 1300 may include an interface 1330 (e.g., a network interface) that provides a component for communicating with at least one other device within the core network and with at least one radio access network.

[0172] BS 1300 may be configured to perform any one or more of the operations described herein (e.g., as described above in conjunction with Figure 1-Figure 9 As described and in combination with Figure 14-15In some aspects of the present disclosure, the processor 1304 as used in the BS 1300 may include circuits configured for various functions.

[0173] Processor 1304 may be configured to generate, schedule, and modify resource allocations or grants for time-frequency resources (e.g., a set of one or more resource elements). For example, processor 1304 may schedule time-frequency resources within multiple time division duplex (TDD) and / or frequency division duplex (FDD) subframes, time slots, and / or micro-slots to carry user data traffic and / or control information to and / or from multiple UEs. Processor 1304 may be configured to schedule resources for transmission of downlink signals (e.g., SSB). Processor 1304 may also be configured to schedule resources for transmission of uplink signals.

[0174] In some aspects of the present disclosure, the processor 1304 may include a communication and processing circuit 1341. The communication and processing circuit 1344 may be configured to communicate with the UE. The communication and processing circuit 1341 may include one or more hardware components that provide a physical structure for performing various processes related to communication as described herein (e.g., signal reception and / or signal transmission). The communication and processing circuit 1341 may also include one or more hardware components that provide a physical structure for performing various processes related to signal processing as described herein (e.g., processing received signals and / or processing signals for transmission). The communication and processing circuit 1341 may also be configured to execute the communication and processing software 1351 included on the computer-readable medium 1306 to implement one or more functions described herein.

[0175] The communication and processing circuit 1341 may also be configured to send a message to the UE. For example, the message is included in a MAC-CE carried in a PUSCH, a DCI in a PUCCH or a PUSCH, a random access message, or an RRC message.

[0176] In some implementations where the communication involves receiving information, the communication and processing circuitry 1341 may obtain information from a component of the BS 1300 (e.g., from a transceiver 1310 that receives information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium), process (e.g., decode) the information, and output the processed information. For example, the communication and processing circuitry 1341 may output the information to another component of the processor 1304, the memory 1305, or the bus interface 1308. In some examples, the communication and processing circuitry 1341 may receive one or more of a signal, a message, other information, or any combination thereof. In some examples, the communication and processing circuitry 1341 may receive information via one or more channels. In some examples, the communication and processing circuitry 1341 may include the functionality of a component for receiving. In some examples, the communication and processing circuitry 1341 may include the functionality of a component for decoding.

[0177] In some implementations where communication involves sending (e.g., transmitting) information, the communication and processing circuitry 1341 may obtain information (e.g., from the processor 1304, the memory 1305, or another component of the bus interface 1308), process (e.g., encode) the information, and output the processed information. For example, the communication and processing circuitry 1341 may output the information to the transceiver 1310 (e.g., which sends the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium). In some examples, the communication and processing circuitry 1341 may send one or more of a signal, a message, other information, or any combination thereof. In some examples, the communication and processing circuitry 1341 may send information via one or more channels. In some examples, the communication and processing circuitry 1341 may include functionality of a component for sending (e.g., a component for sending). In some examples, the communication and processing circuitry 1341 may include functionality of a component for encoding.

[0178] The processor 1304 may include: a PCI selection circuit 1342 configured to perform PCI selection related operations as discussed herein (e.g., as described above in conjunction with Figure 8 and Fig. 91306). The PCI selection circuit 1342 may include functionality for determining components of a selection process. In addition, the PCI selection circuit 1342 may include functionality for sending components for PCI selection indications. For example, the PCI selection circuit 1342 may determine whether the UE uses an implicit rule to determine a timing reference for SSB measurements or uses explicit signaling from the BS to determine the timing reference for SSB measurements. In addition, the PCI selection circuit 1342 may generate information for transmission indicating that an implicit rule or a specific PCI indicated by explicit signaling will be used by the UE. The PCI selection circuit 1342 may also be configured to execute PCI selection software 1352 included on the computer-readable medium 1306 to implement one or more functions described herein.

[0179] Processor 1304 may include: mobility circuit 1343, configured to perform mobility-related operations as discussed herein (e.g., as described above in conjunction with Figure 8 and Fig. 9 As described). The mobility circuit 1343 may include functionality of a component for receiving measurement reports. For example, the mobility circuit 1343, in cooperation with the communication and processing circuit 1341, may monitor measurement report messages on uplink resources (e.g., PUSCH) scheduled for the UE to transmit such messages. The mobility circuit 1343 may include functionality of a component for performing mobility operations. For example, the mobility circuit 1343 may process measurement reports received from one or more UEs over time and filter information in the reports (e.g., calculating an average received power metric over a period of time). In addition, based on the information, the mobility circuit 1343 may identify cells / TRPs to be included in the UE's set of candidate cells / TRPs and / or identify the cell / TRP that is most suitable for serving the UE (e.g., for a period of time until this decision is made again). The mobility circuit 1343 may also be configured to execute mobility software 1353 included on the computer-readable medium 1306 to implement one or more functions described herein.

[0180] Fig.14 1400 is a flow chart illustrating an example wireless communication method 1400 according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for implementation of all examples. In some examples, the method 1400 may be composed of Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.13 In some examples, method 1400 may be performed by any BS or scheduling entity shown in any of the above. Fig.13 The method 1400 may be performed by the processing system 1314 of the embodiment of the present invention. In some examples, the method 1400 may be performed by any suitable device or apparatus for performing the functions or algorithms described below.

[0181] At block 1402, the BS may send a physical cell identifier (PCI) selection indication to the user equipment, wherein the PCI selection indication specifies a selection process for selecting a timing reference associated with a PCI for synchronization signal block (SSB) measurements. Fig.13 The PCI selection circuit 1342 shown and described may determine whether the UE uses an implicit rule to determine the timing reference for SSB measurement or uses explicit signaling from the BS to determine the timing reference for SSB measurement. Fig.13 The PCI selection circuit 1342 shown and described, along with the communication and processing circuit 1341 and the transceiver 1310, may transmit or broadcast information indicating whether the UE is to use an implicit rule or a specific PCI indicated by explicit signaling.

[0182] In some examples, the SSB measurement may be for a change in a primary cell, a change in a secondary cell, or a change in a primary and secondary cell. In some examples, the SSB measurement may include a protocol layer 3 measurement. In some examples, the SSB measurement may be based on an SSB measurement timing configuration (SMTC).

[0183] In some examples, the PCI selection indication may specify that the UE is to select a timing reference using predefined rules. In some examples, the PCI selection indication may specify that the UE is to select a timing reference from a subset of multiple candidate PCIs for the UE using predefined rules. In some examples, the subset may include multiple selected PCIs for serving the UE. In some examples, the PCI selection indication may specify that the UE is to select a timing reference from a set of candidate PCIs for at least one serving cell of the UE using predefined rules. In some examples, the PCI selection indication may specify that the UE is to select a specific timing reference associated with the lowest PCI value. In some examples, the PCI selection indication may specify that the UE is to select a specific timing reference associated with the highest PCI value.

[0184] In some examples, the PCI selection indication may specify that the UE is to use a specific timing reference identified by the base station. In some examples, the processing may also include selecting a specific timing reference and sending an indication of the specific timing reference to the UE. In some examples, selecting a specific timing reference may include selecting a specific timing reference from a subset of a candidate PCI set for the UE. In some examples, selecting a specific timing reference may include selecting a specific timing reference from a candidate PCI set for at least one serving cell of the UE. In some examples, sending an indication of a specific timing reference may include sending an indication of a specific timing reference via a downlink control information (DCI), a media access control-control element (MAC-CE), or a radio resource control (RRC) message.

[0185] At block 1404, the BS may receive a measurement report from the UE after sending the PCI selection indication. For example, the mobility circuit 1343 cooperates with the communication and processing circuit 1341 and the transceiver 1310 as described above. Fig.13 As shown and described, a message including measurement report information may be received from a UE. In some examples, the measurement report may be based on a specific timing reference selected by the UE according to a PCI selection indication.

[0186] At block 1406, the BS may perform mobility operations for the UE based on the measurement report. For example, the mobility circuit 1343 may determine whether to change a PCI in a candidate PCI set for the UE or a PCI in a subset of PCIs selected to serve the UE based on the measurement report.

[0187] Fig.15 is a flow chart illustrating an example wireless communication method 1500 according to some aspects. In some examples, the method 1500 may be combined with Fig.14 The method 1400 is implemented (for example, except Fig.14 As described below, in certain implementations within the scope of the present disclosure, some or all of the illustrated features may be omitted, and some of the illustrated features may not be required for implementation of all examples. In some examples, method 1500 may be implemented by Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.13 In some examples, method 1500 may be performed by any BS or scheduling entity shown in any of the above. Fig.13 The method 1500 may be executed by the processing system 1314 of the embodiment of the present invention. In some examples, the method 1500 may be executed by any suitable device or component for performing the functions or algorithms described below.

[0188] At block 1502, the BS may select a timing reference. Fig.13 The PCI selection circuit 1342 shown and described may determine that the UE is to use a particular timing reference (eg, the timing of the anchor cell) for SSB measurements.

[0189] At block 1504, the BS may send an indication of the timing reference to the user equipment. For example, PCI selection circuit 1342 together with communication and processing circuit 1341 and transceiver 1310, as described above in conjunction with Fig.13 As shown and described, the indication may be sent in a DCI sent on the PDCCH or in a MAC-CE or RRC message sent on the PDSCH.

[0190] The following provides a summary of several aspects of the disclosure.

[0191] Aspect 1: A method for wireless communication at a user equipment, the method comprising: receiving a first indication of a set of candidate physical cell identifiers (PCIs) of the user equipment from a base station; selecting a first PCI from the set of candidate PCIs; determining a timing reference for synchronization signal block (SSB) measurement based on a downlink reception timing associated with the first PCI; and performing SSB measurement using the timing reference.

[0192] Aspect 2: The method according to aspect 1 also includes: receiving a second indication of a subset of the candidate PCI set from the base station, wherein selecting the first PCI from the candidate PCI set includes selecting the first PCI from the subset.

[0193] Aspect 3: The method according to Aspect 2, wherein the subset includes only the first PCI.

[0194] Aspect 4: A method according to any one of Aspects 1 to 3, wherein the first sending and receiving point of the first service cell of the user equipment is identified by the second PCI in the candidate PCI set, and the second sending and receiving point of the first service cell is identified by the third PCI in the candidate PCI set.

[0195] Aspect 5: A method according to any one of Aspects 1 to 4, wherein the first service cell for the user equipment is identified by a second PCI in the candidate PCI set, and the second service cell for the user equipment is identified by a third PCI in the candidate PCI set.

[0196] Aspect 6: The method according to any one of aspects 1 to 5, wherein the candidate PCI set includes multiple PCIs for at least one serving cell of the user equipment.

[0197] Aspect 7: A method according to Aspect 6, wherein: the first PCI includes an anchor PCI for the user equipment; the anchor PCI is associated with at least one of a broadcast service, a control service, a measurement reporting service, or any combination thereof; and at least one of the multiple PCIs is associated with a data service.

[0198] Aspect 9: The method according to any one of Aspects 1 to 7 further includes: receiving a PCI selection indication from the base station; and using the PCI selection indication to select the first PCI.

[0199] Aspect 10: The method according to aspect 9, wherein the PCI selection indication specifies that the user equipment is to select the first PCI using a predefined rule.

[0200] Aspect 11: The method according to aspect 10 further includes: receiving a second indication of a subset of the candidate PCI set from the base station; and selecting the first PCI from the subset using the predefined rule.

[0201] Aspect 12: A method according to any one of Aspects 10 to 11, wherein: the candidate PCI set includes multiple PCIs of at least one service cell of the user equipment; and the method also includes using the predefined rule to select the timing reference from the multiple PCIs.

[0202] Aspect 13: The method according to any one of aspects 10 to 12, wherein the predefined rule specifies that the user equipment is to select a PCI associated with a lowest PCI value or a highest PCI value.

[0203] Aspect 14: The method according to any one of aspects 9 to 13, wherein the PCI selection indication specifies that the user equipment is to use a specific PCI identified by the base station.

[0204] Aspect 15: The method according to Aspect 14 further includes: receiving an indication of the specific PCI from the base station.

[0205] Aspect 16: A method according to any one of Aspects 1 to 7 and 9 to 15, wherein: the candidate PCI set is associated with multiple transmit receive points (TRPs) of the service cell of the user equipment; or, the candidate PCI set is associated with multiple service cells of the user equipment.

[0206] Aspect 17: A method for wireless communication at a base station, the method comprising: sending a physical cell identifier (PCI) selection indication to a user equipment, wherein the PCI selection indication specifies a selection process for selecting a timing reference associated with the PCI for synchronization signal block (SSB) measurement; after sending the PCI selection indication, receiving a measurement report from the user equipment; and performing mobility operations on the user equipment based on the measurement report.

[0207] Aspect 18: The method according to aspect 17, wherein the PCI selection indication specifies that the user equipment is to select the timing reference using a predefined rule.

[0208] Aspect 19: The method according to any one of aspects 17 to 18, wherein the PCI selection indication specifies that the user equipment is to use a predefined rule to select the timing reference from a subset of the candidate PCI set of the user equipment.

[0209] Aspect 20: The method according to aspect 19, wherein the subset includes a plurality of selected PCIs for serving the user equipment.

[0210] Aspect 21: A method according to any one of aspects 17 to 20, wherein the PCI selection indication specifies that the user equipment is to use a predefined rule to select the timing reference from a set of candidate PCIs of at least one serving cell of the user equipment.

[0211] Aspect 22: The method according to any one of aspects 17 to 21, wherein the PCI selection indication specifies that the user equipment is to select a specific timing reference associated with a lowest PCI value.

[0212] Aspect 23: The method according to any one of aspects 1 to 22, wherein the PCI selection indication specifies that the user equipment is to select a specific timing reference associated with a highest PCI value.

[0213] Aspect 24: The method according to any one of aspects 17 to 23, wherein the PCI selection indication specifies that the user equipment is to use a specific timing reference identified by the base station.

[0214] Aspect 26: A method according to any one of Aspects 17 to 24, wherein: the PCI selection indication specifies that the user equipment will use a specific timing reference identified by the base station; and the method also includes selecting the specific timing reference and sending an indication of the specific timing reference to the user equipment.

[0215] Aspect 27: The method according to Aspect 26 further comprises: selecting the specific timing reference from a subset of a candidate PCI set for the user equipment.

[0216] Aspect 28: The method according to any one of aspects 26 to 27 further includes: selecting the specific timing reference from a set of candidate PCIs for at least one serving cell of the user equipment.

[0217] Aspect 29: The method according to any one of Aspects 26 to 28 also includes: sending the indication of the specific timing reference through downlink control information (DCI), media access control-control element (MAC-CE) or radio resource control (RRC) message.

[0218] Aspect 30: The method according to any one of aspects 17 to 24 and aspects 26 to 29, wherein the measurement report is based on a specific timing reference selected by the user equipment according to the PCI selection indication.

[0219] Aspect 31: A user equipment comprising: a transceiver configured to communicate with a radio access network; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor and the memory are configured to perform any one of aspects 1 to 7 and aspects 9 to 16.

[0220] Aspect 32: An apparatus configured for wireless communication, comprising at least one component for performing any one of aspects 1 to 7 and aspects 9 to 16.

[0221] Aspect 33: A non-transitory computer-readable medium storing computer-executable code, comprising code for causing an apparatus to perform any one of aspects 1 to 7 and aspects 9 to 16.

[0222] Aspect 34: A base station comprising: a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory, wherein the processor and the memory are configured to perform any one of aspects 17 to 24 and aspects 26 to 30.

[0223] Aspect 35: An apparatus configured for wireless communication, comprising at least one component for performing any one of aspects 17 to 24 and aspects 26 to 30.

[0224] Aspect 36: A non-transitory computer-readable medium storing computer-executable code, comprising code for causing an apparatus to perform any one of aspects 17 to 24 and aspects 26 to 30.

[0225] Several aspects of wireless communication networks have been presented with reference to example implementations. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures, and communication standards.

[0226] For example, various aspects may be implemented in other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System Mobile (GSM). Various aspects may also be extended to systems defined by the Third Generation Partnership Project 2 (3GPP2), such as CDMA2000 and / or Evolution Data Optimized (EV-DO). Other examples may be implemented in systems employing Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems. The actual telecommunication standard, network architecture, and / or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

[0227] In the present disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration". Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as being preferred or advantageous over other aspects of the present disclosure. Likewise, the term "various aspects" does not require that all aspects of the present disclosure include the discussed features, advantages, or modes of operation. The term "coupled" as used herein refers to a direct or indirect coupling between two objects. For example, if object A is in physical contact with object B, and object B is in contact with object C, objects A and C can still be considered to be coupled to each other—even if they are not in direct physical contact. For example, a first object can be coupled to a second object even if the first object has never been in direct physical contact with the second object. The term "circuit" is used broadly and is intended to include hardware implementations of electrical devices and conductors that, when connected and configured, are capable of performing the functions described in the present disclosure, without limiting the types of electronic circuits and software implementations of information and instructions that, when executed by a processor, are capable of performing the functions described in the present disclosure. As used herein, the term "determining" may include, for example, determining, resolving, selecting, choosing, establishing, calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), and the like. Additionally, "determining" may include receiving (eg, receiving information), accessing (eg, accessing data in a memory) and the like.

[0228] Figure 1-Figure 15 One or more components, steps, features and / or functions shown may be rearranged and / or combined into a single component, step, feature or function, or may be embodied in several components, steps or functions. Additional elements, components, steps and / or functions may also be added without departing from the novel features disclosed herein. Figure 1 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.13 The devices, apparatuses and / or components shown in the can be configured to perform one or more methods, features or steps described herein. The novel algorithms described herein can also be effectively implemented in software and / or embedded in hardware.

[0229] It should be understood that the specific order or hierarchy of steps in the disclosed methods is a diagram of an example process. Based on design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in an example order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

[0230] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be clear to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but to conform to the full scope consistent with the language of the claims, wherein the elements mentioned in the singular are not intended to mean "one and only one", unless otherwise specified, but "one or more". Unless otherwise expressly stated, the term "some" refers to one or more. Phrases referring to a list of "at least one" items refer to any combination of these items, including single members. For example, "at least one of a, b, or c" is intended to cover: a; b; a and b; a and c; b and c; and a, b, and c. All structural and functional equivalents of the elements of the various aspects described in this disclosure that are known or will be known later by those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be included in the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims.

Claims

1. A method for wireless communication at a user equipment, the method comprising: receiving a first indication of a candidate physical cell identifier (PCI) set of the user equipment from a base station; receiving a downlink signal associated with a first PCI selected by the user equipment from the set of candidate PCIs; as well as Synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs are measured according to a timing reference based on a downlink reception timing derived from a downlink signal associated with the first PCI.

2. The method according to claim 1, further comprising: receiving a second indication of a subset of the candidate PCI set from the base station, and The first PCI is selected from the subset.

3. The method according to claim 2, wherein: The subset includes only the first PCI.

4. The method according to claim 1, wherein: The first transmission and reception point of the first serving cell of the user equipment is identified by a second PCI in the candidate PCI set, and the second transmission and reception point of the first serving cell is identified by a third PCI in the candidate PCI set.

5. The method according to claim 1, wherein: The first serving cell of the user equipment is identified by a second PCI in the candidate PCI set, and the second serving cell of the user equipment is identified by a third PCI in the candidate PCI set.

6. The method according to claim 1, wherein: The candidate PCI set includes a plurality of PCIs of at least one serving cell of the user equipment.

7. The method according to claim 6, wherein: The first PCI includes an anchor PCI of the user equipment; The anchor PCI is associated with at least one of a broadcast service, a control service, a measurement report service, or any combination thereof; and At least a second PCI of the plurality of PCIs is associated with a data service.

8. The method according to claim 1, further comprising: receiving a PCI selection indication from the base station; as well as The first PCI is selected using the PCI selection indication.

9. The method according to claim 8, wherein: The PCI selection indication specifies that the user equipment is to select the first PCI using a predefined rule.

10. The method according to claim 9, further comprising: receiving, from the base station, a second indication of a subset of the candidate PCI set; as well as The first PCI is selected from the subset using the predefined rule.

11. The method according to claim 9, wherein: The candidate PCI set includes a plurality of PCIs of at least one serving cell of the user equipment; and The method also includes selecting the first PCI from the plurality of PCIs using the predefined rule.

12. The method according to claim 9, wherein: The predefined rule specifies that the user equipment is to select the PCI associated with the lowest PCI value or the highest PCI value.

13. The method according to claim 8, wherein: The PCI selection indication specifies that the user equipment is to use a particular PCI identified by the base station.

14. The method according to claim 13, further comprising: An indication of the specific PCI is received from the base station.

15. The method of claim 1, wherein: The candidate PCI set is associated with a plurality of transmission and reception points TRPs of a serving cell of the user equipment; or The candidate PCI set is associated with a plurality of serving cells of the user equipment.

16. An apparatus for wireless communication, comprising: one or more memories storing processor-executable code; and one or more processors configured to execute the processor executable code and cause the apparatus to: receiving, via a transceiver, from a base station, a first indication of a set of candidate physical cell identifiers (PCIs) of the apparatus; receiving, via the transceiver, a downlink signal associated with a first PCI selected by the apparatus from the set of candidate PCIs; and Synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs are measured according to a timing reference based on a downlink reception timing derived from a downlink signal associated with the first PCI.

17. The device according to claim 16, wherein: The one or more processors are further configured to execute the processor executable code and cause the apparatus to: receiving a PCI selection indication from the base station; and The first PCI is selected using the PCI selection indication.

18. The device according to claim 17, wherein: The PCI selection indication specifies that the device is to select the first PCI using predefined rules.

19. The device according to claim 18, wherein: The one or more processors are further configured to execute the processor executable code and cause the apparatus to: receiving from the base station a second indication of a subset of the candidate PCI set; and The first PCI is selected from the subset using a predefined rule.

20. The apparatus of claim 18, wherein: The candidate PCI set includes a plurality of PCIs of at least one serving cell of the apparatus; and The one or more processors are further configured to execute the processor-executable code and cause the apparatus to select the first PCI from the plurality of PCIs using a predefined rule.

21. The device according to claim 18, wherein The predefined rule specifies that the device selects the PCI associated with the lowest PCI value or the highest PCI value.

22. The device according to claim 17, wherein: The PCI selection indication specifies that the device is to use a particular PCI identified by the base station.

23. The device according to claim 22, wherein: The one or more processors are further configured to execute the processor executable code and cause the apparatus to: An indication of the specific PCI is received from the base station.

24. The apparatus of claim 16, wherein: The candidate PCI set is associated with a plurality of transmission reception points TRPs of a serving cell of the apparatus; or The candidate PCI set is associated with a plurality of serving cells of the apparatus.

25. The device according to claim 16, wherein: The one or more processors are further configured to execute the processor executable code and cause the apparatus to: receiving from the base station a second indication of a subset of the candidate PCI set; and The first PCI is selected from the subset.

26. The device according to claim 25, wherein The subset includes only the first PCI.

27. The device according to claim 16, wherein: The one or more processors are further configured to execute the processor executable code and cause the apparatus to: identifying a first transmission / reception point of a first serving cell of the device based on a second PCI of the candidate PCI set; and A second transmission / reception point of the first serving cell is identified based on a third PCI of the candidate PCI set.

28. The apparatus of claim 16, wherein the one or more processors are further configured to execute the processor-executable code and cause the apparatus to: identifying a first serving cell of the apparatus based on a second PCI of the candidate PCI set; and A second serving cell for the apparatus is identified based on a third PCI of the set of candidate PCIs.

29. A user equipment, comprising: means for receiving a first indication of a set of candidate physical cell identifiers (PCIs) of the user equipment from a base station; means for receiving a downlink signal associated with a first PCI selected by the user equipment from the set of candidate PCIs; and Means for measuring synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs according to a timing reference based on a downlink reception timing derived from a downlink signal associated with the first PCI.

30. A non-transitory computer-readable medium having stored therein instructions executable by one or more processors of a user device to: receiving a first indication of a candidate physical cell identifier (PCI) set of the user equipment from a base station; receiving a downlink signal associated with a first PCI selected by the user equipment from the set of candidate PCIs; as well as Synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs are measured according to a timing reference based on a downlink reception timing derived from a downlink signal associated with the first PCI.

31. A method of wireless communication at a base station, the method comprising: Sending a physical cell identifier (PCI) selection indication to a user equipment, wherein the PCI selection indication specifies a selection process for selecting a timing reference for synchronization signal block (SSB) measurement, the timing reference being associated with a first PCI from a set of candidate PCIs of the user equipment; After sending the PCI selection indication, receiving a measurement report from the user equipment, wherein the measurement report is determined by measuring synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs according to a timing reference, the timing reference being based on a downlink reception timing derived from a downlink signal associated with the first PCI; and A mobility operation is performed on the user equipment based on the measurement report.

32. The method according to claim 31, wherein: The PCI selection indication specifies that the user equipment is to select the timing reference using a predefined rule.

33. The method according to claim 31, wherein: The PCI selection indication specifies that the user equipment is to use predefined rules to select the timing reference from a subset of a set of candidate PCIs.

34. The method of claim 33, wherein: The subset includes a plurality of selected PCIs for serving the user equipment.

35. The method of claim 31, wherein: The candidate PCI set is a candidate PCI set of at least one serving cell of the user equipment, and wherein the PCI selection indication specifies that the user equipment is to use a predefined rule to select the timing reference from the candidate PCI set of at least one serving cell of the user equipment.

36. The method of claim 31, wherein: The PCI selection indication specifies that the user equipment is to select a particular timing reference associated with a lowest PCI value.

37. The method of claim 31, wherein: The PCI selection indication specifies that the user equipment is to select a particular timing reference associated with a highest PCI value.

38. The method of claim 31, wherein: The PCI selection indication specifies that the user equipment is to use a particular timing reference identified by the base station.

39. A base station, comprising: Transceiver; Memory; as well as a processor communicatively coupled to the transceiver and the memory, wherein the processor and the memory are configured to: Sending, by the transceiver, a physical cell identifier (PCI) selection indication to a user equipment, wherein the PCI selection indication specifies a selection process for selecting a timing reference for synchronization signal block (SSB) measurement, the timing reference being associated with a first PCI from a set of candidate PCIs of the user equipment; After sending the PCI selection indication, receiving, by the transceiver, a measurement report from the user equipment, wherein the measurement report is determined by measuring synchronization signal blocks (SSBs) associated with at least two PCIs in the set of candidate PCIs according to a timing reference, the timing reference being based on a downlink reception timing derived from a downlink signal associated with the first PCI; and A mobility operation is performed on the user equipment based on the measurement report.

40. The base station of claim 39, wherein: The PCI selection indication specifies that the user equipment is to use a specific timing reference associated with a specific PCI identified by the base station; and The processor and the memory are further configured to select the specific PCI and send an indication of the specific PCI to the user equipment.

41. The base station according to claim 40, wherein: The processor and the memory are further configured to: The particular PCI is selected from a subset of the set of candidate PCIs.

42. The base station according to claim 40, wherein: The candidate PCI set is a candidate PCI set of at least one serving cell of the user equipment, and the processor and the memory are further configured to: The specific PCI is selected from a candidate PCI set of at least one serving cell of the user equipment.

43. The base station according to claim 40, wherein: The processor and the memory are further configured to: The indication of the specific PCI is sent through downlink control information DCI, medium access control-control element MAC-CE or radio resource control RRC message.

44. A base station, comprising: Means for performing the steps of the method according to any one of claims 31-38.

45. A non-transitory computer-readable medium having stored therein instructions executable by one or more processors of a base station to perform the method according to any one of claims 31-38.

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