TAG maintenance, update and signaling

Abstract

A method of wireless communication at a UE is disclosed. The method comprises receiving an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, where each cell group of the set of cell groups comprises a plurality of cells, where a first cell group of the set of cell groups is associated with a pTAG and a second cell group of the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. The method also includes receiving L1 signaling or L2 signaling that associates the second group of cells with the pTAG and associates the first group of cells with the sTAG.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Application Serial No. 63 / 373,442, filed on August 24, 2022, entitled “TAG MAINTENANCE, UPDATE, AND SIGNALING,” and U.S. Non-Provisional Patent Application Serial No. 18 / 357,938, filed on July 24, 2023, entitled “TAG MAINTENANCE, UPDATE, AND SIGNALING,” the entireties of which are expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to communication systems, and more particularly to a timing advance group (TAG). Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5GNR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). Certain aspects of 5G NR may be based on 4G Long Term Evolution (LTE) standards. It is necessary to further improve 5G NR technology. In addition, these improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is presented below to provide a basic understanding of these aspects. This summary is not an extensive review of all contemplated aspects. This summary neither identifies the key or important elements of all aspects, nor describes the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description presented later.

[0007] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a user equipment (UE) are provided. The apparatus includes at least one memory and at least one processor coupled to the at least one memory, and based at least in part on information stored in the at least one memory, the at least one processor is configured to: receive a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; and receive L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG.

[0008] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a network entity are provided. The apparatus includes at least one memory and at least one processor coupled to the at least one memory, and based at least in part on information stored in the at least one memory, the at least one processor is configured to: send a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups of a user equipment (UE), wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; and send L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG.

[0009] To achieve the aforementioned and related purposes, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail some exemplary features of one or more aspects. However, these features indicate only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0011] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0012] Figure 2B is a diagram illustrating an example of downlink (DL) channels within a subframe according to various aspects of the present disclosure.

[0013] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0014] Figure 2D is a diagram illustrating an example of uplink (UL) channels within a subframe according to various aspects of the present disclosure.

[0015] Figure 3 is a diagram illustrating an example of a base station and a user equipment (UE) in an access network.

[0016] Figure 4 is a diagram illustrating an example cell designation.

[0017] Figure 5 is a diagram illustrating an example of a cell group belonging to a timing advance group (TAG).

[0018] Figure 6 is a diagram illustrating an example of a cell group belonging to a TAG.

[0019] Figure 7 is a diagram illustrating example TAG identifiers (IDs) for different cells.

[0020] Figure 8 is a diagram illustrating an example of changing a TAG ID for a different cell.

[0021] Fig. 9 is a diagram illustrating an example medium access control (MAC) control element (MAC-CE) for changing a TAG ID.

[0022] Fig.10 is a diagram illustrating an example of a cell group belonging to a TAG and an active TAG group.

[0023] Fig.11 is a diagram illustrating an example of a cell group belonging to a TAG and an active TAG group.

[0024] Fig.12 is a diagram illustrating a cell group configured with an incremental TAG.

[0025] Fig.13is a diagram illustrating example communications between a UE and a base station.

[0026] Fig.14 is a flow chart of a wireless communication method.

[0027] Fig.15 is a flow chart of a wireless communication method.

[0028] Fig.16 is a flow chart of a wireless communication method.

[0029] Fig.17 is a flow chart of a wireless communication method.

[0030] Fig.18 are diagrams illustrating examples of hardware implementations for example apparatuses and / or network entities.

[0031] Fig.19 is a diagram illustrating an example of a hardware implementation for an example network entity. DETAILED DESCRIPTION

[0032] A cell may be configured for L1 or L2 mobility. Cells and / or cell groups within a cell set configured for L1 / L2 mobility may be associated with different TAGs, wherein the TAG may be associated with a timing advance (TA), which the UE may apply to communications via / with / through cells belonging to the TAG. When the identity of a special cell (SpCell) changes within a cell set configured for L1 / L2 mobility and the new SpCell is not within the same TAG as the previous SpCell, the base station may change the pTAG and sTAG associations, i.e., the base station may send signaling associating the ID for the pTAG with the cell group currently associated with the sTAG and associating the ID for the sTAG with the cell group currently associated with the pTAG. The base station may change the TAG association of the SCell via RRC signaling. However, RRC signaling (i.e., Layer 3 (L3) signaling) may be time consuming. In addition, the number of available TAG IDs may be limited, and the number of cell groups in the cell set of the L1 / L2 mobility configuration may exceed the number of available TAG IDs. Various techniques for TAG maintenance, updating, and signaling are disclosed herein. In one example, a UE receives an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. The UE receives L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. The pTAG / sTAG association may be updated based on the L1 signaling or the L2 signaling for communication between the UE and cells belonging to the pTAG / sTAG without the UE receiving RRC signaling (which may be time consuming as described above). Therefore, the L1 signaling or the L2 signaling may be associated with increased communication reliability. Also disclosed herein are various techniques for managing TAG IDs when the number of cell groups exceeds the number of available TAG IDs.

[0033] The specific embodiments described below in conjunction with the accompanying drawings are descriptions of various configurations and do not represent the only configurations in which the concepts described herein can be practiced. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0034] Several aspects of telecommunication systems are presented with reference to various apparatus and methods. These apparatus and methods are described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0035] As an example, an element, or any part of an element, or any combination of elements can be implemented as a "processing system", which includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform various functionalities described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.

[0036] Thus, in one or more example aspects, specific implementations and / or use cases, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functionality may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available media that can be accessed by a computer. As an example, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0037] Although various aspects, specific implementations and / or use cases are described in this application by the illustration of some examples, additional or different aspects, specific implementations and use cases may be generated in many different arrangements and scenarios. The various aspects, specific implementations and / or use cases described herein can be implemented across many different platform types, devices, systems, shapes, sizes and packaging arrangements. For example, various aspects, specific implementations and / or use cases can be generated via integrated chip specific implementations and other devices based on non-module components (e.g., end-user devices, vehicles, communication equipment, computing equipment, industrial equipment, retail / purchase equipment, medical equipment, devices that enable artificial intelligence (AI), etc.). Although some examples may or may not be specifically for use cases or applications, the described examples may have wide applicability. Various aspects, specific implementations and / or use cases can be in the range from chip-level or modular components to non-modular, non-chip-level specific implementations, and further to the range of aggregated, distributed or original equipment manufacturer (OEM) equipment or systems in conjunction with one or more technologies herein. In some actual settings, the equipment combined with the various aspects and features described may also include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.) The various techniques described herein can be practiced in a wide variety of devices of various sizes, shapes, and configurations, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc.

[0038] The deployment of a communication system (such as a 5G NR system) can be arranged with various components or constituent parts in a variety of ways. In a 5G NR system or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element or a network equipment (such as a base station (BS), or one or more units (or one or more components) that perform base station functionality can be implemented in an aggregated or decomposed architecture. For example, a BS (such as a Node B (NB), an evolved NB (eNB), an NR BS (e.g., a gNB), a 5G NB, an access point (AP), a transmit receive point (TRP) or a cell, etc.) can be implemented as an aggregated base station (also referred to as an independent BS or a monolithic BS) or a decomposed base station.

[0039] A converged base station may be configured to utilize a radio protocol stack physically or logically integrated within a single RAN node. A decomposed base station may be configured to utilize a protocol stack physically or logically distributed between two or more units, such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed in one or more other RAN nodes. A DU may be implemented to communicate with one or more RUs. Each of a CU, a DU, and a RU may be implemented as a virtual unit, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU).

[0040] Base station operation or network design may take into account the aggregated nature of base station functionality. For example, a disaggregated base station may be used in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (network configuration such as that initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)). Decomposition may include distributing functionality across two or more units at various physical locations, as well as virtually distributing functionality of at least one unit, which may enable flexibility in network design. Individual units of a disaggregated base station or disaggregated RAN architecture may be configured for wired or wireless communication with at least one other unit.

[0041] Figure 1 1 is a diagram 100 illustrating an example of a wireless communication system and an access network. The illustrated wireless communication system includes a disaggregated base station architecture. The disaggregated base station architecture may include one or more CUs 110 that may communicate directly with a core network 120 via a backhaul link, or indirectly with the core network 120 through one or more disaggregated base station units, such as a near real-time (near RT) RAN intelligent controller (RIC) 125 via an E2 link, or a non-real-time (non-RT) RIC 115 associated with a service management and orchestration (SMO) framework 105, or both. The CU 110 may communicate with one or more DUs 130 via corresponding midhaul links, such as an F1 interface. The DU 130 may communicate with one or more RUs 140 via corresponding fronthaul links. The RU 140 may communicate with corresponding UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 140.

[0042] Each of the units (i.e., CU 110, DU 130, RU 140, and near-RT RIC 125, non-RT RIC 115, and SMO framework 105) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively referred to as signals) via a wired or wireless transmission medium. Each of these units or an associated processor or controller that provides instructions to the communication interface of these units may be configured to communicate with one or more of the other units via a transmission medium. For example, these units may include a wired interface configured to receive signals or send signals to one or more of the other units via a wired transmission medium. Additionally, these units may include a wireless interface that may include a receiver, transmitter, or transceiver (such as an RF transceiver) configured to receive and / or send signals to one or more of the other units via a wireless transmission medium.

[0043] In some aspects, CU 110 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may be implemented using an interface configured to communicate signals with other control functions hosted by CU 110. CU110 may be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some specific implementations, CU 110 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 110 may be implemented to communicate with DU 130 for network control and signaling.

[0044] DU 130 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 140. In some aspects, DU 130 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) at least in part according to a functional split such as those defined by 3GPP. In some aspects, DU 130 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 130 or with control functions hosted by CU 110.

[0045] The lower layer functionality may be implemented by one or more RUs 140. In some deployments, the RU 140 controlled by the DU 130 may correspond to a logical node that hosts RF processing functions or low PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on functional splitting (such as lower layer functional splitting). In such an architecture, the RU 140 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some implementations, real-time and non-real-time aspects of communicating with the control plane and user plane of the RU 140 may be controlled by the corresponding DU 130. In some scenarios, this configuration may enable the implementation of the DU 130 and the CU 110 in a cloud-based RAN architecture (such as a vRAN architecture).

[0046] The SMO framework 105 may be configured to support RAN deployment and provisioning of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 105 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 105 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 190) to perform network element lifecycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 110, DU 130, RU 140, and near-RT RIC 125. In some specific implementations, the SMO framework 105 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 111) via the O1 interface. Additionally, in some specific implementations, the SMO framework 105 may communicate directly with one or more RUs 140 via the O1 interface. The SMO framework 105 may also include a non-RT RIC 115 configured to support the functionality of the SMO framework 105 .

[0047] The non-RT RIC 115 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence (AI) / machine learning (ML) (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 125. The non-RT RIC 115 may be coupled to or communicate with the near-RT RIC 125 (such as via an A1 interface). The near-RT RIC 125 may be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 110, one or more DUs 130, or both, and the O-eNB with the near-RT RIC 125.

[0048] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 125, the non-RT RIC 115 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 125 and may be received from a non-network data source or from a network function at the SMO framework 105 or the non-RT RIC 115. In some examples, the non-RT RIC 115 or the near-RT RIC 125 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 115 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 105 (such as via reconfiguration of O1) or via the creation of RAN management policies (such as A1 policies).

[0049] At least one of the CU 110, the DU 130, and the RU 140 may be referred to as a base station 102. Therefore, the base station 102 may include one or more of the CU 110, the DU 130, and the RU 140 (each component is indicated by a dotted line to indicate that each component may be included in the base station 102 or may not be included in the base station). The base station 102 provides an access point to the core network 120 for the UE 104. The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). Small cells include femto cells, pico cells, and micro cells. A network including both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG). The communication link between RU 140 and UE 104 may include uplink (UL) (also known as reverse link) transmission from UE 104 to RU 140 and / or downlink (DL) (also known as forward link) transmission from RU 140 to UE 104. The communication link may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link may be through one or more carriers. For each carrier allocated in a carrier aggregation of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz, etc.) bandwidth. These carriers may or may not be adjacent to each other. The allocation of carriers may be equivalent to DL and UL asymmetric (e.g., more or fewer carriers may be allocated to DL than to UL). Component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

[0050] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL wireless wide area network (WWAN) spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, Bluetooth, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0051] The wireless communication system may also include a Wi-Fi AP 150 that communicates with a UE 104 (also referred to as a Wi-Fi station (STA)) via a communication link 154, for example, in a 5 GHz unlicensed spectrum, etc. When communicating in an unlicensed spectrum, the UE 104 / AP 150 may perform a clear channel assessment (CCA) to determine whether a channel is available prior to communication.

[0052] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as the "sub-6 GHz" band in various documents and articles. A similar naming issue sometimes occurs with respect to FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although different from the extremely high frequency (EHF) band (30 GHz-300 GHz) identified as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0053] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125GHz-24.25GHz). The bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, so the features of FR1 and / or FR2 can be effectively extended to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to more than 52.6GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6GHz-71GHz), FR4 (71GHz-114.25GHz) and FR5 (114.25GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

[0054] In view of the above, unless otherwise specified, if the term "6 GHz or less" is used herein, it may broadly refer to frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specified, if the term "millimeter wave" is used herein, it may broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2, and / or FR5, or may be within the EHF band.

[0055] The base station 102 and the UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming. The base station 102 may send a beamformed signal 182 to the UE 104 in one or more transmit directions. The UE 104 may receive the beamformed signal from the base station 102 in one or more receive directions. The UE 104 may also send a beamformed signal 184 to the base station 102 in one or more transmit directions. The base station 102 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 102 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 102 / UE 104. The transmit direction and receive direction of the base station 102 may be the same or different. The transmit direction and receive direction of the UE 104 may be the same or different.

[0056] The base station 102 may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), a network node, a network entity, a network equipment, or some other suitable term. The base station 102 may be implemented as an integrated access and backhaul (IAB) node, a relay node, a sidelink node, an aggregated (monolithic) base station with a baseband unit (BBU) (including a CU and a DU) and a RU, or as a decomposed base station including one or more of a CU, a DU, and / or a RU. A set of base stations that may include decomposed base stations and / or aggregated base stations may be referred to as a next generation (NG) RAN (NG-RAN).

[0057] The core network 120 may include an access and mobility management function (AMF) 161, a session management function (SMF) 162, a user plane function (UPF) 163, a unified data management (UDM) 164, one or more location servers 168, and other functional entities. AMF 161 is a control node that handles signaling between UE 104 and core network 120. AMF 161 supports registration management, connection management, mobility management, and other functions. SMF 162 supports session management and other functions. UPF 163 supports packet routing, packet forwarding, and other functions. UDM 164 supports the generation of authentication and key agreement (AKA) credentials, user identity handling, access authorization, and subscription management. One or more location servers 168 are illustrated as including a gateway mobile location center (GMLC) 165 and a location management function (LMF) 166. However, in general, the one or more location servers 168 may include one or more location / positioning servers, which may include one or more of the GMLC 165, LMF 166, position determination entity (PDE), serving mobile location center (SMLC), mobile positioning center (MPC), etc. GMLC 165 and LMF 166 support UE location services. GMLC 165 provides an interface for clients / applications (e.g., emergency services) to access UE positioning information. LMF 166 receives measurement and assistance information from NG-RAN and UE 104 via AMF 161 to calculate the location of UE 104. NG-RAN may determine the location of UE 104 using one or more positioning methods. Positioning UE 104 may involve signal measurements, position estimation, and optional speed calculation based on these measurements. Signal measurements may be performed by UE 104 and / or serving base station 102. The measured signals may be based on a satellite positioning system (SPS) 170 (e.g., one or more of a global navigation satellite system (GNSS), a global positioning system (GPS), a non-terrestrial network (NTN), or other satellite positioning / positioning systems), LTE signals, wireless local area network (WLAN) signals, Bluetooth signals, a terrestrial beacon system (TBS), sensor-based information (e.g., an atmospheric pressure sensor, a motion sensor), an NR enhanced cell ID (NR E-CID) method, NR signals (e.g., multi-round trip time (multi-RTT), DL angle of departure (DL-AoD), DL time difference of arrival (DL-TDOA), UL time difference of arrival (UL-TDOA), and UL angle of arrival (UL-AoA) positioning), and / or one or more of other systems / signals / sensors.

[0058] Examples of UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet computers, smart devices, wearable devices, vehicles, electric meters, gas pumps, large or small kitchen appliances, healthcare equipment, implants, sensors / actuators, displays, or any other similarly functional devices. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as stations, mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, mobile phones, user agents, mobile clients, clients, or some other suitable terminology. In some scenarios, the term UE may also be applied to one or more supporting devices, such as in a device cluster arrangement. One or more of these devices may access the network collectively and / or individually.

[0059] Reference again Figure 1 In certain aspects, the UE 104 may be configured with a TAG component 198 configured to: receive an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA; and receive L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. In certain aspects, the base station 102 may be configured with a TAG component 199 configured to: send an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups for the UE, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA; and send L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. Although the following description may focus on 5G NR, the concepts described herein may be applicable to other similar fields, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0060] Figure 2AFIG200 is a diagram illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2D FIG280 is a diagram illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL, or may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , Figure 2C In the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with the slot format through the received slot format indicator (SFI) (dynamically configured through DL control information (DCI) or semi-statically / statically configured through radio resource control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure as TDD.

[0061] FIG. 2A to FIG. 2DThe frame structure is illustrated, and various aspects of the present disclosure may be applicable to other wireless communication technologies that may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes of equal size (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For a normal CP, each time slot may include 14 symbols, and for an extended CP, each time slot may include 12 symbols. The symbol on the DL may be a CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) extended OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of slots in a subframe is based on the CP and the parameter set. The parameter set defines the subcarrier spacing (SCS) (see

[0062] Table 1). Symbol length / duration can be scaled with 1 / SCS.

[0063]

[0064] Table 1: Parameter set, SCS and CP

[0065] For normal CP (14 symbols / slot), different parameter sets μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For extended CP, parameter set 2 allows 4 slots per subframe. Thus, for normal CP and parameter set μ, there are 14 symbols / slot and 2 μ timeslots / subframe. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is parameter set 0 to 4. Therefore, the subcarrier spacing for parameter set μ=0 is 15kHz, and the subcarrier spacing for parameter set μ=4 is 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIG. 2A to FIG. 2D An example is provided for a normal CP with 14 symbols per slot and a parameter set μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is about 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP may have a specific parameter set and CP (normal or extended).

[0066] A resource grid may be used to represent the frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0067] like Figure 2A As illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0068] Figure 2B Examples of various DL channels within a subframe of a frame are illustrated. A physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies on the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not sent via the PBCH (such as a system information block (SIB)), and paging messages.

[0069] like Figure 2CAs illustrated, some of the REs carry DM-RS (indicated as R for a particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may send a DM-RS for a physical uplink control channel (PUCCH) and a DM-RS for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first or first two symbols of the PUSCH. Depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used, the PUCCH DM-RS may be sent in different configurations. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The SRS may be used by the base station for channel quality estimation to achieve frequency-dependent scheduling of the UL.

[0070] Figure 2D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located at a position as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACKs and / or negative ACKs (NACKs)). The PUSCH carries data and may be used to carry, among other things, a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0071] Figure 3375. The Controller / Processor 375 is a block diagram of a base station 310 in an access network communicating with a UE 350. In the DL, Internet Protocol (IP) packets may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with delivery of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0072] The transmit (TX) processor 316 and receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-order phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be separated into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially pre-coded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived from reference signals and / or channel state feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318Tx. Each transmitter 318Tx may modulate a radio frequency (RF) carrier for transmission using a corresponding spatial stream.

[0073] At the UE 350, each receiver 354Rx receives a signal through its corresponding antenna 352. Each receiver 354Rx recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by base station 310. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functionality.

[0074] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0075] Similar to the functionality described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with delivery of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0076] Channel estimates derived by the channel estimator 358 based on a reference signal or feedback sent by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354Tx. Each transmitter 354Tx may modulate an RF carrier with a corresponding spatial stream for transmission.

[0077] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318Rx receives a signal through its respective antenna 320. Each receiver 318Rx recovers information modulated onto an RF carrier and provides the information to the RX processor 370.

[0078] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0079] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 The TAG component 198 combines various aspects.

[0080] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 The TAG component 199 combines various aspects.

[0081] Figure 4 400 is a diagram illustrating an example of dual connectivity and carrier aggregation (CA). UE 402 may be connected to a master cell group (MCG) 404 and a secondary cell group (SCG) 406. This arrangement may be referred to as dual connectivity (DC) 408. MCG 404 may be a group of serving cells associated with a master node having a control plane connection to a core network (e.g., core network 120). The master node may be a base station such as a gNB, eNB, etc. (i.e., a network entity). SCG 406 may be a group of serving cells associated with a secondary node that does not have a control plane connection to the core network. The secondary node may be a base station such as a gNB, eNB, etc. (i.e., a network entity). Based on various factors such as the location of UE 402, network status, etc., MCG 404 may become SCG 406 and SCG 406 may become MCG 404.

[0082] The MCG 404 may include a PCell 410. The MCG 404 may also include one or more SCells (e.g., a first SCell 412 and an Nth SCell 414, where N is a positive integer greater than one). The PCell 410, the first SCell 412, and / or the Nth SCell 414 may be in a CA 416 configuration. In some aspects, based on various factors such as the location of the UE 402, network status, etc., a primary cell may become a secondary cell or a secondary cell may become a primary cell.

[0083] The SCG 406 includes a primary secondary cell (PSCell) 418. The PSCell 418 is the primary cell of the SCG 406. The SCG 406 may also include one or more SCells (e.g., a first SCell 420 and an Mth SCell 422, where M is a positive integer greater than one). The PSCell 418, the first SCell 420, and / or the Mth SCell 422 may be in a CA configuration 424. In some aspects, based on various factors such as the location of the UE 402, network status, etc., the primary secondary cell may become a secondary cell or the secondary cell may become a primary secondary cell.

[0084] The PCell 410 of the MCG 404 and the PSCell 418 of the SCG 406 may be referred to as a special cell (SpCell) 426. For dual connectivity operations, the term SpCell refers to the PCell of the MCG or the PSCell of the SCG, for example, depending on whether the MAC entity is associated to the MCG or the SCG, respectively. The SpCell supports PUCCH transmission and contention-based random access and may always be activated. The SpCell 426 is responsible for data and control functionality. In the absence of a DC (for example, when the MCG 404 is configured and when the SCG 406 is not configured), the PCell 410 may be referred to as the SpCell 426. The cell group including the SpCell 426 may be referred to as a PCG. It should be understood that the SpCell may change based on various factors such as the location of the UE 402, the network status, etc. In one example, the network entity may configure the first SCell 412 as a primary cell and the M SCell 422 as a primary secondary cell to configure a new SpCell.

[0085] Figure 5 5 is a diagram illustrating an example of a cell group belonging to a TAG. A TAG may also be referred to as a timing adjustment group. A base station may configure a cell set 502 for L1 / L2 mobility configuration of a UE 504 via RRC. Fig.13 1300 is a diagram depicting an example communication between a UE 1302 and a base station 1304. In one example, at 1306, the UE 1302 may receive an L1 / L2 mobility cell configuration sent by the base station 1304. The L1 / L2 mobility cell configuration may use L1 and / or L2 signaling to facilitate inter-cell mobility. In one example, a cell set 502 of the L1 / L2 mobility configuration may include a first cell group (CG1) 506, a second cell group (CG2) 508, a third cell group (CG3) 510, and a fourth cell group (CG4) 512 (collectively referred to as "CG 506-512"). Each of the CG506-512 may include multiple cells (represented by triangles in the diagram 500).

[0086] The base station may send L1 / L2 signaling that activates the CG for data and control transfer to the UE 504, i.e., the L1 / L2 signaling may place the CG in the L1 / L2 mobility activated cell set 514. The L1 signaling may include DCI signaling. The L2 signaling may include MAC-CE signaling. For example, refer to Fig.13At 1308, the UE 1302 may receive L1 / L2 signaling to activate the CGs within the L1 / L2 mobility configured cell set 502. In one example, the base station sends L1 / L2 signaling to place CG1 506 and CG2 508 within the L1 / L2 mobility activated cell set 514. CGs (e.g., CG3 510 and CG4 512) that are not within the L1 / L2 mobility activated cell set 514 may be activated (such CGs may be used for data and control transfer) and added to the L1 / L2 mobility activated cell set 514 via further L1 / L2 signaling. In addition, CGs may be removed from the L1 / L2 mobility activated cell set 514 via further L1 / L2 signaling.

[0087] The UE may receive the assignment of CG to TAG from the base station. Fig.13 At 1310, the UE 1302 may receive a TAG identifier (ID) configuration via RRC, wherein the TAG ID configuration may associate a CG to a different TAG. Each TAG may have a unique ID. The base station may assign a CG to a TAG based on frequency band operation, the presence of a repeater (a repeater may introduce additional delay in UL transmissions), cell location, and / or UE location. When a SCell is added to a cell set 502 of an L1 / L2 mobility configuration, the base station may associate the SCell to a TAG.

[0088] When a CG or a cell is assigned to a TAG, the CG / cell may belong to a TAG. The cells in the cell set 502 of the L1 / L2 mobility configuration may belong to the same TAG or different TAGs. For example, a group of collocated component carriers (CCs) may belong to the same TAG. There may be multiple non-collocated CCs within the cell set 502 of the L1 / L2 mobility configuration. Cells belonging to the same TAG may be associated with the same TA. When the UE 504 is connected to a cell belonging to a TAG associated with a TA, the UE 504 may use the TA for communication via / with / through each cell belonging to the TAG.

[0089] TA may refer to the negative offset between the start of a DL time slot and the start of a UL time slot at UE 504 as observed by UE 504. TA may account for propagation delays so that the UE's UL and DL transmissions are aligned at a reference point. Generally speaking, a first UE located relatively far from a base station may start UL transmissions relatively sooner than a second UE located relatively close to the base station. Thus, the first UE may apply a larger TA to UL transmissions than the TA applied by the second UE.

[0090] A TAG including a PCell (or SpCell) may be designated as a pTAG. In one example, CG1 506 may include a cell used as a PCell 516. Therefore, CG1 506 may belong to a pTAG 518. A TAG not including a PCell (or SpCell) may be designated as an sTAG. In one example, CG2 508 may belong to a first sTAG (sTAG1) 520, CG4 512 may belong to a second sTAG (sTAG2) 522, and CG3 510 may belong to a third sTAG (sTAG3) 524. In one example, pTAG 518, sTAG1 520, sTAG2 522, and sTAG3 524 may be associated with different TAs.

[0091] When the UE 504 initially connects to CG1 506 including a cell serving as the PCell 516, the UE 504 may perform a RACH procedure with the PCell 516 to obtain a TA associated with the pTAG 518. For the SCell, the UE 504 may receive a PDCCH order from the base station. Upon receiving the PDCCH order, the UE may perform a contention-free RACH procedure on the SCell belonging to the sTAG (e.g., sTAG1 520, sTAG2 522, sTAG3 524, etc.) to obtain a TA associated with the sTAG.

[0092] In a wireless communication system, the network may aim to ensure that the UE maintains connectivity with a network entity (e.g., a base station) when the UE moves within the network. Inter-cell mobility based on L1 / L2 may help reduce mobility latency. For example, the configuration and maintenance of multiple candidate cells may allow for rapid application of configurations for candidate cells. In addition, a dynamic switching mechanism between candidate serving cells (including SpCells and SCells) based on L1 / L2 signaling may further reduce latency.

[0093] Inter-cell mobility based on L1 / L2 is applicable to independent operation scenarios, CA scenarios, and DC (e.g., NR-DC) scenarios. In independent operation scenarios and CA scenarios, inter-cell mobility based on L1 / L2 is applicable to intra-DU situations and / or intra-CU inter-DU situations. Inter-cell mobility based on L1 / L2 is applicable in both FR1 and FR2 and in both intra-frequency and inter-frequency. In inter-cell mobility based on L1 / L2, the source cell and the target cell can be synchronized or asynchronous.

[0094] When the identity of the SpCell changes within the set of cells configured for L1 / L2 mobility and the new SpCell is not within the same TAG as the previous SpCell, the base station may change the pTAG and sTAG associations, i.e., the base station may send a signaling that associates the ID for the pTAG with the cell group currently associated with the sTAG and associates the ID for the sTAG with the cell group currently associated with the pTAG. The base station may change the TAG association of the SCell via RRC signaling. However, RRC signaling (i.e., layer 3 signaling) may be time consuming. In addition, the number of available TAG IDs may be limited, and the number of cell groups in the set of cells configured for L1 / L2 mobility may exceed the number of available TAG IDs. Various techniques for TAG maintenance, updating, and signaling are disclosed herein. In one example, a UE receives an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first timing TA and the sTAG is associated with a second TA. The UE receives L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. The pTAG / sTAG association may be updated based on the L1 signaling or the L2 signaling for communication between the UE and cells belonging to the pTAG / sTAG without the UE receiving RRC signaling (which may be time consuming as described above). Thus, the L1 signaling or the L2 signaling may be associated with increased communication reliability. Various techniques for managing TAG IDs when the number of cell groups exceeds the number of available TAG IDs are also disclosed herein.

[0095] Figure 6 600 is a diagram illustrating an example of a group of cells belonging to a TAG. In the example depicted in diagram 600, UE 504 has moved from a first location to a second location (compared to diagram 500). The base station may send L1 / L2 signaling to UE 504 that changes the identity of a PCell 516 (or SpCell) within the cell set 502 of the L1 / L2 mobility configuration. For example, in diagram 600 and in contrast to diagram 500, the cell within CG2 508 is now PCell 516. For example, referring to Fig.13 At 1312, UE 1302 may receive L1 / L2 signaling sent by base station 1304, wherein the L1 / L2 signaling changes the identifier of the SpCell.

[0096] Since the identity of the PCell 516 (or SpCell) has changed and the new cell (cell in CG2 508) used as the PCell 516 belongs to a different TAG than the previous cell (cell in CG1 506) used as the PCell 516, the base station may switch the pTAG 518 and sTAG1 520 associations. In other words, the pTAG reference update may be used for the deactivated sTAG. As depicted in diagram 600, the base station may send L1 / L2 signaling to the UE 504 to associate the pTAG 518 with the CG2 508 and the sTAG1 520 with the CG1506. The pTAG / sTAG association update may be based on a configured set of TAG IDs for each cell (or cell group) within the cell set 502 configured for L1 / L2 mobility. The pTAG association update (which may be referred to as a specified update) may be implicit and based on a SpCell specified update.

[0097] In one example, the base station may assign unique TAG IDs to CGs 506-512 that correspond to their respective TAGs. The base station may swap unique TAG IDs when the association of pTAG 518 changes (e.g., from being associated with CG1 506 to being associated with CG2 508). For example, the base station may swap TAG ID "0" associated with CG1 506 to CG2 508, and the base station may swap TAG ID "1" associated with CG2 508 to CG1 506.

[0098] For example, refer to Fig.13 At 1314, UE 1302 may receive L1 / L2 signaling for changing the pTAG / sTAG association sent by base station 1304. At 1316, the UE may update the pTAG / sTAG association based on the L1 / L2 signaling received at 1314. A base station that sends L1 / L2 signaling for changing the pTAG / sTAG association may change the pTAG / sTAG association faster than a base station that changes the pTAG / sTAG association using RRC signaling.

[0099] Figure 7700 is a diagram illustrating example TAG identifiers (IDs) for different cells. Diagram 700 depicts a first cell 702, a second cell 704, and a third cell 706 (collectively referred to as "cells 702-706"). In one example, the first cell 702 may belong to CG1 506, the second cell 704 may belong to CG2 508, and the third cell 706 may belong to CG4 512. As part of the initial configuration, a UE (e.g., UE 504) may receive a serving cell configuration 708 that associates each of the cells 702-706 with a set of TAG IDs 710. The set of TAG IDs 710 may include "0", "1", and "2". The serving cell configuration 708 may also associate each of the cells 702-706 with a TAG ID in the set of TAG IDs 710. In one example, the serving cell configuration 708 may associate the first cell 702 with "0" in the set of TAG IDs 710, i.e., the first cell 702 may be associated with pTAG 712 (i.e., assigned to pTAG 712, belongs to pTAG 712). The serving cell configuration 708 may associate the second cell 704 with "1" in the set of TAG IDs 710, i.e., the second cell 704 may be associated with sTAG1 714 (i.e., assigned to sTAG1 714, belongs to sTAG1 714). The serving cell configuration 708 may associate the third cell 706 with "2" in the set of TAG IDs 710, i.e., the third cell 706 may be associated with sTAG2 716 (i.e., assigned to sTAG2 716, belongs to sTAG2 716). Cells belonging to the same TAG may be assigned the same TAG ID at the same time. Each of the set of TAG IDs 710 may be associated with the same or a different TA.

[0100] In one aspect, serving cell configuration 708 may conform to the following format:

[0101]

[0102] Figure 8 800 is a diagram illustrating an example of changing the TAG ID for different cells. As described above in the description of diagram 700, diagram 800 includes a first cell 702 belonging to pTAG 712, a second cell 704 belonging to sTAG1 714, and a third cell 706 belonging to sTAG2 716. In other words, the serving cell configuration 708 described in the description of diagram 700 may associate the first cell 702 with tag ID "0", the second cell 704 with tag ID "1", and the third cell 706 with tag ID "2".

[0103] The base station may send L1 / L2 signaling 802 (e.g., DCI or MAC-CE) to a UE (e.g., UE 504) to change the TAG association of cells 702-706. When a new cell used as a SpCell belongs to a different TAG than the previous cell used as the SpCell, the L1 / L2 signaling 802 may be used to select a TAG ID to use. For example, the L1 / L2 signaling 802 may associate the first cell 702 with sTAG1714 and the second cell 704 with pTAG 712. For example, referring to Fig.13 At 1314, UE 1302 may receive L1 / L2 signaling sent by base station 1304 to change the pTAG / sTAG association, i.e., the L1 / L2 signaling may associate a cell or a cell group with a different TAG ID. At 1316, UE 1302 may update the pTAG / sTAG association based on the L1 / L2 signaling received at 1314.

[0104] In one aspect, the L1 / L2 signaling 802 may be explicit L1 / L2 signaling. For example, the L1 / L2 signaling 802 may include a TAG ID for the UE to apply when the pTAG changes. In one example, the L1 / L2 signaling 802 may include an identifier for the first cell 702 and an indication that TAG ID "1" will be associated with the first cell 702, an identifier for the second cell 704 (i.e., the new SpCell) and an indication that TAG ID "0" will be associated with the second cell 704. When the UE communicates via / with / through the first cell 702, the UE may apply the first TA associated with sTAG1 based on TAG ID "1". When the UE communicates via / with / through the second cell 704, the UE may apply the second TA associated with the pTAG based on TAG ID "0".

[0105] In one aspect where the L1 / L2 signaling 802 is explicit, the L1 / L2 signaling 802 may be dedicated L1 / L2 signaling. For example, the UE may receive L1 / L2 signaling that changes the identity of the SpCell (or PCell), and the UE may separately receive L1 / L2 signaling 802 that changes the pTAG / sTAG association. For example, referring to Fig.13 At 1312, UE 1302 may receive a (first) L1 / L2 signaling to change the identity of the SpCell. At 1314, UE 1302 may receive a (second) L1 / L2 signaling to change the pTAG / sTAG association.

[0106] In one aspect where L1 / L2 signaling 802 is explicit, L1 / L2 signaling 802 may be joint L1 / L2 signaling. For example, L1 / L2 signaling 802 may change (1) the identity of the SpCell (or PCell) and (2) the pTAG / sTAG association. For example, referring to Fig.13 At 1314, UE 1302 may receive L1 / L2 signaling to change the identity of the SpCell and to change the pTAG / sTAG association.

[0107] In one aspect, the L1 / L2 signaling 802 may be implicit L1 / L2 signaling. For example, the L1 / L2 signaling 802 may change the identity of the SpCell (or PCell). The L1 / L2 signaling 802 may not include a TAG ID. When the UE receives the L1 / L2 signaling 802, if the cell to be used as the new SpCell belongs to a different TAG than the cell used as the current SpCell, the UE may autonomously exchange the TAGIDs (e.g., for the first cell 702, exchange TAG ID "0" with TAG ID "1", and for the second cell 704, exchange TAG ID "1" with TAG ID "0"). For example, referring to Fig.13 At 1312, changing the L1 / L2 signaling of the SpCell may implicitly change the pTAG / sTAG association at 1316. The base station may also update the TAG ID association.

[0108] Fig. 9 900 is a diagram illustrating an example MAC-CE for changing a TAG ID. In some aspects, the number of CGs in the cell set 502 of the L1 / L2 mobility configuration may be greater than the number of available TAG IDs configured by the serving cell configuration 708. In one example, the number of available TAG IDs may be four. The UE may receive a configuration to increase the number of available TAG IDs via RRC signaling. In one example, the configuration may increase the number of available TAG IDs from four to sixteen. For example, referring to Fig.13 At 1310, UE 1302 may receive a TAG ID configuration that increases the number of available TAG IDs via RRC signaling.

[0109] In one aspect, the L1 / L2 signaling may include a MAC-CE 902. The MAC-CE 902 may include a TAG ID 904 and a timing advance command 906. The TAG ID 904 may be two bits wide. To accommodate a number of TAG IDs greater than four (e.g., sixteen), the MAC-CE 902 may be associated with a logical channel index (LCID) 908. The combination of the LCID 908 and the TAG ID 904 may indicate a TAG. In one example, LCID "0" may be associated with TAGs 0-4, LCID "1" may be associated with TAGs 5-8, LCID "2" may be associated with TAGs 9-12, and LCID "3" may be associated with TAGs 13-15. Bits in the TAG ID 904 may be utilized to sub-select a particular TAG. In one example, when the LCID 908 is "1" and the TAG ID 904 is "10," the MAC-CE 902 may indicate TAG7. In one example, referring to Fig.13 At 1314 , the L1 / L2 signaling received by the UE 1302 may include the MAC-CE 902 and the LCID 908 .

[0110] In one aspect, the L1 / L2 signaling may include a MAC-CE 910. The MAC-CE 910 may include a TAG ID 912 and a timing advance command 914. The TAG ID 912 may be four bits wide to accommodate sixteen available TAG IDs. Fig.13 At 1314 , the L1 / L2 signaling received by the UE 1302 may include the MAC-CE 910 .

[0111] Fig.10 1000 is a diagram illustrating an example of a cell group belonging to a TAG and an active TAG group. An active TAG group may refer to a set of cells in which a TAG ID associated with each cell is active and valid. As described above, the number of CGs in the cell set 502 configured for L1 / L2 mobility may be greater than the number of available TAG IDs configured by the serving cell configuration 708. In the example depicted in diagram 1000, four TAG IDs may be available, and six CGs (CG1 506, CG2 508, CG3 510, CG4 512, a fifth cell group (CG5) 1002, and a sixth cell group (CG6) 1004) are within the cell set 502 configured for L1 / L2 mobility.

[0112] In one aspect, the base station may define an active TAG group 1006. The active TAG group may include the CGs that the UE 504 is currently communicating via / with / through and the CGs that the UE 504 is predicted to communicate via / with / through in the future. In diagram 1000, the active TAG group 1006 includes CG1 506 and CG2 508 (the CGs that the UE 504 is currently communicating via / with / through) and CG3 510 and CG4 512 (the CGs that the UE 504 is predicted to communicate via / with / through in the future). The prediction about which CGs the UE 504 is predicted to communicate via / with / through in the future may be based on the location of the UE 504, measurement reports sent by the UE 504, and / or frequency bands associated with these CGs. The prediction may be made by the UE 504 or the base station.

[0113] CGs within the active TAG group 1006 may be synchronized with the UE 504. CGs that are not within the active CG (e.g., CG5 1002 and CG6 1004) may not be synchronized with the UE 504. For example, a CG within the active TAG group 1006 may be assigned a Boolean information element "cell synchronization = true", and a CG that is not within the active TAG group 1006 may be assigned Boolean information "cell synchronization = false". Since CG5 1002 and CG6 1004 are not synchronized with the UE 504 (i.e., "cell synchronization = false"), the UE 504 may ignore TAGn 1008 associated with CG5 1002 and CG6 1004.

[0114] For example, refer to Fig.13 At 1318, the UE 1302 may receive an indication of an active TAG group sent by the base station 1304. The UE 1302 may ignore TAGs of CGs within the set of cells 502 of the L1 / L2 mobility configuration that are not within the active TAG group.

[0115] Fig.11 1000 is a diagram illustrating an example of a cell group belonging to a TAG and an active TAG group. In diagram 1000, UE 504 has moved from a first location (depicted in diagram 1000) to a second location. Thus, the base station may send L1 / L2 signaling to change the pTAG / sTAG association. As depicted in diagram 1000, UE 504 has received L1 / L2 signaling to associate pTAG 518 with CG3 510, sTAG1 520 with CG5, and sTAG3 524 with CG6 1004. In addition, the composition of the active TAG group 1006 may change.

[0116] In one example, reference Fig.13At 1319, the UE 1302 may perform a measurement (or multiple measurements) on the DL-RS associated with the CG (e.g., CG5 1002, CG6 1004, etc.). In one aspect, at 1320, the UE may predict a change to the active TAG group 1006 based on the measurement, the location of the UE 504, and / or the operating frequency associated with the CG. The measurement may be a reference signal received power (RSRP) measurement. At 1322, the UE 1302 may send a measurement report (or multiple measurement reports) including the measurement and / or prediction. At 1324, the UE 1302 may receive modifications to the active TAG group 1006 based on the prediction and / or SpCell change via L1 / L2 signaling.

[0117] In another aspect, reference Fig.13 At 1319, the UE 1302 may perform a measurement (or multiple measurements) on the DL-RS associated with the CG (e.g., CG5 512, CG5 1002, etc.). At 1322, the UE 1302 may send a measurement report (or multiple measurement reports) including the measurement. At 1326, the base station 1304 may predict a change to the active TAG group 1006 based on the measurement, the location of the UE 504, and / or the operating frequency associated with the CG. At 1324, the UE 1302 may receive a modification to the active TAG group 1006 based on the prediction and / or SpCell change via L1 / L2 signaling.

[0118] In one example, L1 / L2 signaling removes CG1 506 and CG2 508 from the active TAG group 1006, and adds CG5 1002 and CG6 1004 to the active TAG group 1006. Since CG1 506 and CG2 508 are no longer within the active TAG group 1006, CG1 506 and CG2 508 have "cell sync = false". CG1 506 and CG2 508 are no longer synchronized with the UE 504, and the UE 504 can ignore the TAGn 1008 now associated with CG1 506 and CG2 508.

[0119] Fig.121200 is an illustration of a cell group configured with an incremental TAG. As described above, the number of CGs in the cell set 502 of the L1 / L2 mobility configuration may be greater than the number of available TAG IDs configured by the serving cell configuration 708. In the example depicted in diagram 1000, four TAG IDs may be available, and six CGs (CG1 506, CG2 508, CG3510, CG4 512, CG51002, and CG6 1004) are within the cell set 502 of the L1 / L2 mobility configuration. The base station may configure a reference TAG ID for CG51002 and CG6 1004. In one example, the reference TAG ID may be TAG0 1202. The reference tag ID may be the same as the TAG ID used for pTAG 518 (e.g., "0"). The base station may also configure the information element "Incremental Tag = True" for CG5 1002 and CG6 1004. Since CG5 1002 and CG6 1004 have "DeltaTag=True", the respective TAs of CG5 1002 and CG6 1004 may be delta-timing relative to the TA associated with the reference TAG. Each cell within CG5 1002 and CG6 1004 may have a provided TA offset compared to the reference TAG.

[0120] For example, refer to Fig.13 At 1310, the TAG ID configuration received by the UE 1302 may include an indication of a reference tag and a TA offset for the cell or CG. The UE 1302 may determine a TA for the cell group based on the TA and TA offset associated with the reference TAG ID.

[0121] Fig.14 1400 is a flow chart of a wireless communication method. The method may be performed by a UE (e.g., UE 104, UE 402, UE 504, UE 1302, device 1804). In one example, the method may be performed by TAG component 198. The method may be associated with various technical advantages at the UE, such as faster changes of pTAG / TAG associations compared to RRC signaling-based methods.

[0122] At 1402, the UE receives an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. For example, Fig.13UE 1302 is shown receiving L1 / L2 mobility cell configuration at 1306. In another example, L1 mobility cell configuration or L2 mobility cell configuration for a set of cell groups may add a set of cell groups to the Figure 5 The cell set 502 of L1 / L2 mobility configuration in Figure 5 In the example depicted in , the first cell group can be CG1 506 and the second cell group can be CG2 508, where CG1 506 can be associated with pTAG 518 and CG2 508 can be associated with sTAG 1520. For example, 1402 can be performed by the TAG component 198.

[0123] At 1404, the UE receives L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG. Fig.13 At 1314, UE 1302 receives L1 / L2 signaling to change pTAG / sTAG association. Figure 6 , L1 signaling or L2 signaling may associate CG1 506 with sTAG1 520 and associate CG2 508 with pTAG 518. In yet another example, L1 signaling or L2 signaling may be Figure 8 1404 may be performed by the TAG component 198, for example.

[0124] Fig.15 1500 is a flow chart of a wireless communication method. The method may be performed by a UE (e.g., UE 104, UE 402, UE 504, UE 1302, device 1804). In one example, the method (including various aspects described below) may be performed by a TAG component 198. The method may be associated with various technical advantages at the UE, such as faster changes of pTAG / TAG associations compared to RRC signaling-based methods.

[0125] At 1502, the UE receives an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. For example, Fig.13 UE 1302 is shown receiving L1 / L2 mobility cell configuration at 1306. In another example, L1 mobility cell configuration or L2 mobility cell configuration for a set of cell groups may add a set of cell groups to the Figure 5 The cell set 502 of L1 / L2 mobility configuration in Figure 5 In the example depicted in , the first cell group may be CG1 506 and the second cell group may be CG2 508, wherein CG1 506 may be associated with pTAG 518 and CG2 508 may be associated with sTAG 1520. For example, 1502 may be performed by TAG component 198.

[0126] At 1508, the UE receives L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG. Fig.13 At 1314, UE 1302 receives L1 / L2 signaling to change pTAG / sTAG association. Figure 6 , L1 signaling or L2 signaling may associate CG1 506 with sTAG1 520 and associate CG2 508 with pTAG 518. In yet another example, L1 signaling or L2 signaling may be Figure 8 1508 may be performed by the TAG component 198, for example.

[0127] In one aspect, at 1510, the UE may update the second cell group to be associated with the pTAG and update the first cell group to be associated with the sTAG based on L1 signaling or L2 signaling. Fig.13 At 1316, UE 1302 is shown updating the pTAG / sTAG association based on the L1 / L2 signaling received at 1314. In another example, reference Figure 6 , UE 504 may associate CG1 506 with sTAG1 520 and associate CG2 508 with pTAG 518 based on L1 signaling or L2 signaling. In another example, L1 signaling or L2 signaling may be Figure 8 1510 may be performed by the TAG component 198, for example.

[0128] In one aspect, at 1504, the UE may receive a TAG ID configuration via RRC signaling, the TAG ID configuration including a first ID for a pTAG and a second ID for a sTAG. Fig.13 At 1310, UE 1302 is shown receiving a TAG ID configuration. In another example, the TAG ID configuration may be Figure 7 The serving cell configuration 708 is shown in FIG. Figure 7In the example of , the pTAG may be pTAG 712 and the sTAG may be sTAG1 714. Tag "0" in the set of TAG IDs 710 may be a first ID and tag "1" in the set of TAG IDs 710 may be a second ID. For example, 1504 may be performed by TAG component 198.

[0129] In one aspect, the first cell group may include a first cell used as a SpCell before receiving L1 signaling or L2 signaling, wherein the second cell group may include a second cell used as a SCell before receiving L1 signaling or L2 signaling. Figure 4 , the first cell may be SpCell 426, and the second cell may be first SCell 420. In another example, referring to Figure 5 , the first cell group may be CG1 506 which may include a PCell 516, and the second cell group may be CG2 508 which may include one or more SCells.

[0130] In one aspect, at 1506, the UE may receive a second L1 signaling or a second L2 signaling that may cause the second cell to function as a SpCell and the first cell to function as a SCell before receiving the L1 signaling or the L2 signaling, wherein the L1 signaling or the L2 signaling may associate the second cell group with the first ID for the pTAG and associate the first cell group with the second ID for the sTAG. For example, Fig.13 At 1312, UE 1302 receives L1 / L2 signaling to change the identity of SpCell. Figure 8 , L1 signaling or L2 signaling can be L1 / L2 signaling 802 (dedicated explicit). For example, 1506 can be performed by the TAG component 198.

[0131] In one aspect, L1 signaling or L2 signaling may cause the second cell to function as a SpCell and the first cell to function as a SCell, wherein the L1 signaling or L2 signaling may indicate that the second cell group will be associated with a first ID for a pTAG and the first cell group will be associated with a second ID for a sTAG. Fig.13 At 1314, it is shown that changing the L1 / L2 signaling of pTAG / sTAG can change the SpCell. In another example, referring to Figure 8 , the L1 signaling or the L2 signaling may be L1 / L2 signaling 802 (joint explicit).

[0132] In one aspect, L1 signaling or L2 signaling may cause the second cell to function as a SpCell and the first cell to function as a SCell, wherein based on receiving the L1 signaling or L2 signaling, the second cell group may be associated with a first ID for a pTAG and the first cell group may be associated with a second ID for a sTAG. For example, Fig.13 At 1312, UE 1302 receives L1 / L2 signaling to change the identity of SpCell. Figure 8 , L1 signaling or L2 signaling can be L1 / L2 signaling 802 (implicit).

[0133] In one aspect, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for the TAG, and the TAG ID configuration may configure a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling may include a MAC-CE associated with the LCID, wherein the MAC-CE and a portion of the LCID may indicate an ID for the TAG. For example, Fig. 9 MAC-CE 902 and LCID 908 are illustrated, where TAG ID 904 of MAC-CE 902 and LCID 908 may indicate an ID for a TAG. In another example, Fig.11 and Fig.12 A scenario is illustrated in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration.

[0134] In one aspect, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for the TAG, wherein the TAG ID configuration may configure a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling may include a MAC-CE, wherein a portion of the MAC-CE may indicate an ID for the TAG. For example, Fig. 9 MAC-CE 910 is illustrated, where TAG ID 912 of MAC-CE indicates an ID for a TAG. In another example, Fig.11 and Fig.12 A scenario is illustrated in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration.

[0135] In one aspect, at 1512, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, and the UE may receive an indication of an active TAG group, wherein the active TAG group may include a first cell group, a second cell group, and a third one or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent point in time, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group. For example, Fig.13 At 1318, UE 1302 is shown receiving an indication of an active TAG group. In another example, Fig.10 An active TAG group 1006 is depicted. The active TAG group 1006 may include the cell group (CG1 506 and CG2 508) with which the UE 504 is currently communicating and the cell group (CG3 510 and CG4 512) with which the UE 504 is predicted to communicate. CG5 1002 and CG6 1004 may not be included in the active TAG group 1006. For example, 1512 may be performed by the TAG component 198.

[0136] In one aspect, the first cell group, the second cell group, and the third one or more cell groups included in the active TAG group may be synchronized with the UE, wherein based on the fourth one or more cell groups not being included in the active TAG group, the fourth one or more cell groups not included in the active TAG group may not be synchronized with the UE. For example, Fig.10 It is shown that CG1 506, CG2 508, CG3 510 and CG4 512 have the information element "Cell Sync = True", and CG5 1002 and CG6 1004 have the information "Cell Sync = False".

[0137] In one aspect, at 1518, the UE may receive a second L1 signaling or a second L2 signaling to modify the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding the fourth one or more cell groups to the active TAG group. For example, Fig.13 At 1324, UE 1302 receives a modification to the active TAG group, and the modification may be received via L1 / L2 signaling. In another example, Fig.11 Removal of CG1 506 and CG2 508 from the active TAG group 1006 and addition of CG5 1002 and CG6 1004 to the active TAG group 1006 based on L1 / L2 signaling are shown. 1518 may be performed by the TAG component 198, for example.

[0138] In one aspect, at 1520, the UE may send data or at least one signal based on L1 signaling or L2 signaling. For example, Fig.13 At 1321, it is shown that the UE 1302 can send data and / or signals based on the L1 signaling or L2 signaling received at 1314. In one example, the UE can send data and / or signals using the first TA or the second TA. For example, 1520 can be performed by the TAG component 198.

[0139] In one aspect, at 1514, the UE may send one or more measurement reports, wherein the second L1 signaling or the second L2 signaling may be based on the one or more measurement reports. Fig.13 At 1319, UE 1302 is shown performing measurements, and Fig.13 The UE 1302 sending a measurement report is shown at 1322. For example, 1514 can be performed by the TAG component 198.

[0140] In one aspect, at 1516, the UE may send a second indication indicating that the UE is predicted to communicate via a fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling may be based on the second indication. Fig.13 At 1320, UE 1302 is shown generating a prediction, and Fig.13 The UE 1302 sending the prediction is shown at 1322. For example, 1516 can be performed by the TAG component 198.

[0141] In one aspect, the second L1 signaling or the second L2 signaling may be based on one or more frequency bands associated with the set of cell groups. Fig.13 , the modification received by UE 1302 at 1324 may be based on one or more frequency bands associated with the set of cell groups. In one example, the one or more frequency bands may be associated with CG1 506, CG2 508, CG3 510, CG4 512, CG5 1002, and / or CG6 1004.

[0142] In one aspect, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the TAG ID configuration may further include a reference TAG ID associated with each of one or more cell groups in the set of cell groups. Fig.12 The scenario in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration is illustrated. The reference TAG ID may be Fig.12 TAG0 1202 as exemplified in .

[0143] In one aspect, a TA for each of the one or more cell groups may be determined based on one or more TA offsets relative to a TA associated with a reference TAG ID, wherein the one or more TA offsets may be included in the TAG ID configuration. Fig.12 , the TA of CG5 1002 and CG6 1004 can be determined based on the TA offset and TAG01202.

[0144] In one aspect, L1 signaling or L2 signaling may be received based on a change in the location of the UE. Figure 5 and Figure 6 The movement of UE 504 is illustrated. For example, referring to Fig.13 , the L1 / L2 signaling received at 1314 may be based on the mobility of UE 504.

[0145] Fig.16 1600 is a flow chart of a wireless communication method. The method may be performed by a network entity (e.g., base station 102, base station 1304, CU 110, DU 130, RU 140, network entity 1802). In one example, the method may be performed by TAG component 199. The method may be associated with various technical advantages at the network entity, such as faster changes of pTAG / TAG associations compared to RRC signaling-based methods.

[0146] At 1602, the network entity sends an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups for the UE, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. For example, Fig.13 The base station 1304 is shown sending the L1 / L2 mobility cell configuration at 1306. In another example, the L1 mobility cell configuration or L2 mobility cell configuration for the set of cell groups may add the set of cell groups to the Figure 5 The cell set 502 of L1 / L2 mobility configuration in Figure 5 In the example depicted in , the first cell group may be CG1 506 and the second cell group may be CG2 508, wherein CG1 506 may be associated with pTAG 518 and CG2 508 may be associated with sTAG1 520. For example, 1602 may be performed by TAG component 199.

[0147] At 1604, the network entity sends L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG. Fig.13At 1314, the base station 1304 sends L1 / L2 signaling to change the pTAG / sTAG association. Figure 6 , L1 signaling or L2 signaling may associate CG1 506 with sTAG1 520 and associate CG2 508 with pTAG 518. In yet another example, L1 signaling or L2 signaling may be Figure 8 1604 may be performed by the TAG component 199, for example.

[0148] Fig.17 1700 is a flow chart of a wireless communication method. The method may be performed by a network entity (e.g., base station 102, base station 1304, CU 110, DU 130, RU 140, network entity 1802). In one example, the method (including various aspects described below) may be performed by TAG component 199. The method may be associated with various technical advantages at the network entity, such as faster changes of pTAG / TAG associations compared to RRC signaling-based methods.

[0149] At 1702, the network entity sends an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups for the UE, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. For example, Fig.13 The base station 1304 is shown sending the L1 / L2 mobility cell configuration at 1306. In another example, the L1 mobility cell configuration or L2 mobility cell configuration for the set of cell groups may add the set of cell groups to the Figure 5 The cell set 502 of L1 / L2 mobility configuration in Figure 5 In the example depicted in , the first cell group may be CG1 506 and the second cell group may be CG2 508, wherein CG1 506 may be associated with pTAG 518 and CG2 508 may be associated with sTAG1 520. For example, 1702 may be performed by the TAG component 199.

[0150] At 1708, the network entity sends L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG. Fig.13 At 1314, the base station 1304 sends L1 / L2 signaling to change the pTAG / sTAG association. Figure 6, L1 signaling or L2 signaling may associate CG1 506 with sTAG1 520 and associate CG2 508 with pTAG 518. In yet another example, L1 signaling or L2 signaling may be Figure 8 1708 may be performed by the TAG component 199, for example.

[0151] In one aspect, at 1704, the network entity may send a TAG ID configuration via RRC signaling, the TAG ID configuration including a first ID for a pTAG and a second ID for a sTAG. Fig.13 At 1310, the base station 1304 sends a TAG ID configuration. In another example, the TAG ID configuration may be Figure 7 The serving cell configuration 708 is shown in FIG. Figure 7 In the example of , the pTAG may be pTAG 712 and the sTAG may be sTAG1 714. Tag "0" in the set of TAG IDs 710 may be a first ID and tag "1" in the set of TAG IDs 710 may be a second ID. For example, 1704 may be performed by TAG component 199.

[0152] In one aspect, the first cell group may include a first cell used as a SpCell before sending L1 signaling or L2 signaling, wherein the second cell group may include a second cell used as a SCell before sending L1 signaling or L2 signaling. Figure 4 , the first cell may be SpCell 426, and the second cell may be first SCell 420. In another example, referring to Figure 5 , the first cell group may be CG1 506 which may include a PCell 516, and the second cell group may be CG2 508 which may include one or more SCells.

[0153] In one aspect, at 1706, the network entity may send a second L1 signaling or a second L2 signaling to use the second cell as the SpCell and the first cell as the SCell before sending the L1 signaling or the L2 signaling, wherein the L1 signaling or the L2 signaling associates the second cell group with the first ID for the pTAG and associates the first cell group with the second ID for the sTAG. For example, Fig.13 At 1312, the base station 1304 sends L1 / L2 signaling to change the identity of the SpCell. Figure 8 , L1 signaling or L2 signaling may be L1 / L2 signaling 802 (dedicated explicit). For example, 1706 may be performed by the TAG component 199 .

[0154] In one aspect, L1 signaling or L2 signaling may cause the second cell to function as a SpCell and the first cell to function as a SCell, wherein the L1 signaling or L2 signaling may indicate that the second cell group will be associated with a first ID for a pTAG and the first cell group will be associated with a second ID for a sTAG. Fig.13 At 1314, it is shown that changing the L1 / L2 signaling of pTAG / sTAG can change the SpCell. In another example, referring to Figure 8 , the L1 signaling or the L2 signaling may be L1 / L2 signaling 802 (joint explicit).

[0155] In one aspect, L1 signaling or L2 signaling may cause the second cell to function as a SpCell and the first cell to function as a SCell, wherein based on sending the L1 signaling or L2 signaling, the second cell group may be associated with a first ID for a pTAG and the first cell group may be associated with a second ID for a sTAG. For example, Fig.13 At 1312, the base station 1304 sends L1 / L2 signaling to change the identity of the SpCell. Figure 8 , L1 signaling or L2 signaling can be L1 / L2 signaling 802 (implicit).

[0156] In one aspect, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for the TAG, wherein the TAG ID configuration may configure a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling may include a MAC-CE associated with an LCID, wherein the MAC-CE and a portion of the LCID may indicate an ID for the TAG. For example, Fig. 9 MAC-CE 902 and LCID 908 are illustrated, where TAG ID 904 of MAC-CE 902 and LCID 908 may indicate an ID for a TAG. In another example, Fig.11 and Fig.12 A scenario is illustrated in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration.

[0157] In one aspect, a first number of cell groups in the set of cell groups is greater than a second number of available IDs for the TAG, wherein the TAG ID configuration may configure a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling may include a MAC-CE, wherein a portion of the MAC-CE may indicate an ID for the TAG. For example, Fig. 9 MAC-CE 910 is illustrated, where TAG ID 912 of MAC-CE indicates an ID for a TAG. In another example, Fig.11 and Fig.12A scenario is illustrated in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration.

[0158] In one aspect, at 1710, a first number of cell groups in the set of cell groups may be greater than a second number of available IDs for TAGs, and the network entity may send an indication of an active TAG group, wherein the active TAG group includes a first cell group, a second cell group, and a third one or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent time point, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group. For example, Fig.13 At 1318, the base station 1304 sends an indication of the active TAG group. In another example, Fig.10 An active TAG group 1006 is depicted. The active TAG group 1006 may include a group of cells (CG1 506 and CG2 508) with which the UE 504 is currently communicating and a group of cells (CG3 510 and CG4 512) with which the UE 504 is predicted to communicate. CG5 1002 and CG6 1004 may not be included in the active TAG group 1006. For example, 1710 may be performed by the TAG component 199.

[0159] In one aspect, the first cell group, the second cell group, and the third one or more cell groups included in the active TAG group may be synchronized with the UE, wherein based on the fourth one or more cell groups not being included in the active TAG group, the fourth one or more cell groups not included in the active TAG group may not be synchronized with the UE. For example, Fig.10 It is shown that CG1 506, CG2 508, CG3 510 and CG4 512 have the information element "Cell Sync = True", and CG5 1002 and CG6 1004 have the information "Cell Sync = False".

[0160] In one aspect, at 1718, the network entity may send a second L1 signaling or a second L2 signaling to modify the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding the fourth one or more cell groups to the active TAG group. For example, Fig.13 At 1324, the base station 1304 sends a modification to the active TAG group, and the modification may be received via L1 / L2 signaling. In another example, Fig.11It is shown that CG1 506 and CG2 508 are removed from the active TAG group 1006 and CG5 1002 and CG6 1004 are added to the active TAG group 1006 based on L1 / L2 signaling. For example, 1718 can be performed by the TAG component 199.

[0161] In one aspect, at 1720, the network entity may receive data or at least one signal based on L1 signaling or L2 signaling. For example, Fig.13 At 1321 it is shown that the base station 1304 can receive data and / or signals based on the L1 signaling or L2 signaling sent at 1314. For example, 1720 can be performed by the TAG component 199.

[0162] In one aspect, at 1712, the network entity may receive one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports. Fig.13 The base station 1304 is shown receiving the measurement report at 1322. For example, 1712 can be performed by the TAG component 199.

[0163] In one aspect, at 1714, the network entity may predict based on the one or more measurement reports that the UE will communicate via a fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling may be based on the prediction. Fig.13 The base station 1304 predicts the active TAG group based on the measurement report at 1326. For example, 1714 can be performed by the TAG component 199.

[0164] In one aspect, at 1716, the network entity may receive a second indication indicating that the UE is predicted to communicate via a fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling may be based on the second indication. Fig.13 The base station 1304 receives the prediction, shown at 1322. For example, 1716 can be performed by the TAG component 199.

[0165] In one aspect, the second L1 signaling or the second L2 signaling may be based on one or more frequency bands associated with the set of cell groups. Fig.13 , the modification sent by the base station 1304 at 1324 may be based on one or more frequency bands associated with the set of cell groups. In one example, the one or more frequency bands may be associated with CG1 506, CG2 508, CG3 510, CG4 512, CG5 1002, and / or CG6 1004.

[0166] In one aspect, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the TAG ID configuration may further include a reference TAG ID associated with each of one or more cell groups in the set of cell groups. Fig.12 The scenario in which four TAG IDs are available and six cell groups are within the cell set 502 of the L1 / L2 mobility configuration is illustrated. The reference TAG ID may be Fig.12 TAG0 1202 as exemplified in .

[0167] In one aspect, a TA for each of the one or more cell groups may be determined based on one or more TA offsets relative to a TA associated with a reference TAG ID, wherein the one or more TA offsets may be included in the TAG ID configuration. Fig.12 , the TA of CG5 1002 and CG6 1004 can be determined based on the TA offset and TAG01202.

[0168] In one aspect, L1 signaling or L2 signaling may be sent based on the change in location of the UE. Figure 5 and Figure 6 The movement of UE 504 is illustrated. For example, referring to Fig.13 , the L1 / L2 signaling received at 1314 may be based on the mobility of UE 504.

[0169] Fig.181800 is a diagram illustrating an example of a hardware implementation for an apparatus 1804. The apparatus 1804 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus 1804 may include a cellular baseband processor 1824 (also referred to as a modem) coupled to one or more transceivers 1822 (e.g., a cellular RF transceiver). The cellular baseband processor 1824 may include on-chip memory 1824'. In some aspects, the apparatus 1804 may also include one or more subscriber identity module (SIM) cards 1820 and an application processor 1806 coupled to a secure digital (SD) card 1808 and a screen 1810. The application processor 1806 may include on-chip memory 1806'. In some aspects, the device 1804 may also include a Bluetooth module 1812, a WLAN module 1814, an SPS module 1816 (e.g., a GNSS module), one or more sensor modules 1818 (e.g., an atmospheric pressure sensor / altimeter; a motion sensor such as an inertial measurement unit (IMU), a gyroscope, and / or an accelerometer; light detection and ranging (LIDAR), radio-aided detection and ranging (RADAR), sound navigation and ranging (SONAR), a magnetometer, audio, and / or other technologies for positioning), an additional memory module 1826, a power source 1830, and / or a camera 1832. The Bluetooth module 1812, the WLAN module 1814, and the SPS module 1816 may include an on-chip transceiver (TRX) (or in some cases, only a receiver (RX)). The Bluetooth module 1812, the WLAN module 1814, and the SPS module 1816 may include their own dedicated antennas and / or communicate using an antenna 1880. The cellular baseband processor 1824 communicates with the UE 104 and / or with the RU associated with the network entity 1802 through the transceiver 1822 via one or more antennas 1880. The cellular baseband processor 1824 and the application processor 1806 may each include a computer-readable medium / memory 1824', 1806', respectively. The additional memory module 1826 may also be considered as a computer-readable medium / memory. Each computer-readable medium / memory 1824', 1806', 1826 may be non-transitory. The cellular baseband processor 1824 and the application processor 1806 are each responsible for general processing, including executing software stored on a computer-readable medium / memory. The software enables the cellular baseband processor 1824 / application processor 1806 to perform the various functions described above when executed by the cellular baseband processor 1824 / application processor 1806. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 1824 / application processor 1806 when executing the software.The cellular baseband processor 1824 / application processor 1806 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the device 1804 may be a processor chip (modem and / or application) and include only the cellular baseband processor 1824 and / or the application processor 1806, and in another configuration, the device 1804 may be the entire UE (e.g., see. Figure 3 350) and includes additional modules of device 1804.

[0170] As discussed above, the TAG component 198 is configured to receive an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. The TAG component 198 is also configured to receive L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. The TAG component 198 may be within the cellular baseband processor 1824, the application processor 1806, or both the cellular baseband processor 1824 and the application processor 1806. The TAG component 198 may be one or more hardware components specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination of the foregoing. As shown, the device 1804 may include a variety of components configured for various functions. In one configuration, the device 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for receiving an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. In one configuration, the device 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for receiving L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes means for updating the second cell group to be associated with the pTAG and the first cell group to be associated with the sTAG based on L1 signaling or L2 signaling. In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes means for receiving a TAG ID configuration via RRC signaling, the TAG ID configuration including a first ID for the pTAG and a second ID for the sTAG.In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for receiving a second L1 signaling or a second L2 signaling to cause the second cell to function as a SpCell and the first cell to function as a SCell before receiving the L1 signaling or the L2 signaling, wherein the L1 signaling or the L2 signaling associates the second cell group with a first ID for a pTAG and associates the first cell group with a second ID for a sTAG. In one configuration, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for receiving an indication of an active TAG group, wherein the active TAG group includes a first cell group, a second cell group, and a third one or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent point in time, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group. In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for receiving a second L1 signaling or a second L2 signaling for modifying the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding a fourth one or more cell groups to the active TAG group. In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for sending one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports. In one configuration, the apparatus 1804, in particular the cellular baseband processor 1824 and / or the application processor 1806, includes a component for sending a second indication indicating that the UE is predicted to communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the second indication. These components may be the TAG components 198 of the apparatus 1804 configured to perform the functions recited by the components. As described above, the apparatus 1804 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, these components may be the TX processor 368, the RX processor 356, and / or the controller / processor 359 configured to perform the functions recited by the components.

[0171] Fig.191900 is a diagram illustrating an example of a hardware implementation for a network entity 1902. The network entity 1902 may be a BS, a component of a BS, or may implement BS functionality. The network entity 1902 may include at least one of a CU 1910, a DU 1930, or a RU 1940. For example, depending on the layer functionality handled by the TAG component 199, the network entity 1902 may include a CU 1910; both a CU 1910 and a DU 1930; each of the CU 1910, the DU 1930, and the RU 1940; the DU 1930; both a DU 1930 and a RU 1940; or a RU 1940. The CU 1910 may include a CU processor 1912. The CU processor 1912 may include an on-chip memory 1912'. In some aspects, the CU 1910 may also include an additional memory module 1914 and a communication interface 1918. CU 1910 communicates with DU 1930 via a midhaul link, such as an F1 interface. DU 1930 may include a DU processor 1932. DU processor 1932 may include on-chip memory 1932'. In some aspects, DU 1930 may also include an additional memory module 1934 and a communication interface 1938. DU 1930 communicates with RU 1940 via a fronthaul link. RU 1940 may include a RU processor 1942. RU processor 1942 may include on-chip memory 1942'. In some aspects, RU 1940 may also include an additional memory module 1944, one or more transceivers 1946, an antenna 1980, and a communication interface 1948. RU 1940 communicates with UE 104. On-chip memory 1912', 1932', 1942' and additional memory modules 1914, 1934, 1944 can each be considered as a computer-readable medium / memory. Each computer-readable medium / memory can be non-transitory. Each of processors 1912, 1932, 1942 is responsible for general processing, including executing software stored on the computer-readable medium / memory. The software, when executed by the corresponding processor, enables the processor to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the processor when executing the software.

[0172] As discussed above, the TAG component 199 is configured to send an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups of the UE, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. The TAG component 199 is configured to send L1 signaling or L2 signaling that associates the second cell group with the pTAG and associates the first cell group with the sTAG. The TAG component 199 may be within one or more processors of one or more of the CU 1910, the DU 1930, and the RU 1940. The TAG component 199 may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination of the foregoing. The network entity 1902 may include a variety of components configured for various functions. In one configuration, the network entity 1902 includes means for sending an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups for the UE, wherein each cell group in the set of cell groups includes a plurality of cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. In one configuration, the network entity 1902 includes means for sending L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG. In one configuration, the network entity 1902 includes means for sending a TAG ID configuration via RRC signaling, the TAG ID configuration including a first ID for the pTAG and a second ID for the sTAG. In one configuration, the network entity 1902 includes a component for sending a second L1 signaling or a second L2 signaling to cause the second cell to function as a SpCell and the first cell to function as a SCell before sending the L1 signaling or the L2 signaling, wherein the L1 signaling or the L2 signaling associates the second cell group with a first ID for a pTAG and associates the first cell group with a second ID for a sTAG. In one configuration, wherein a first number of cell groups in a set of cell groups is greater than a second number of available IDs for TAGs, the network entity 1902 includes a component for sending an indication of an active TAG group, wherein the active TAG group includes a first cell group, a second cell group, and a third one or more cell groups in a set of cell groups via which the UE is predicted to communicate at a first subsequent time point, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group.In one configuration, the network entity 1902 includes a component for sending a second L1 signaling or a second L2 signaling to modify the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding a fourth one or more cell groups to the active TAG group. In one configuration, the network entity 1902 includes a component for receiving one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports. In one configuration, the network entity 1902 includes a component for predicting that the UE will communicate via the fourth one or more cell groups at a second subsequent time point based on the one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the prediction. In one configuration, the network entity 1902 includes a component for receiving a second indication indicating that the UE is predicted to communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the second indication. These components may be the TAG components 199 of the network entity 1902 configured to perform the functions recited by the components. As described above, the network entity 1902 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, these components may be the TX processor 316, the RX processor 370, and / or the controller / processor 375 configured to perform the functions recited by the components.

[0173] The cell may be configured for L1 or L2 mobility. The cells and / or cell groups within the cell set configured for L1 / L2 mobility may be associated with different TAGs, wherein the TAG may be associated with a timing advance (TA), which the UE may apply to communications via / with / through the cells belonging to the TAG. When the identity of a special cell (SpCell) changes within the cell set configured for L1 / L2 mobility and the new SpCell is not within the same TAG as the previous SpCell, the base station may change the pTAG and sTAG associations, i.e., the base station may send a signaling that associates the ID for the pTAG with the cell group currently associated with the sTAG and associates the ID for the sTAG with the cell group currently associated with the pTAG. The base station may change the TAG association of the SCell via RRC signaling. However, RRC signaling (i.e., layer 3 signaling) may be time consuming. In addition, the number of available TAG IDs may be limited, and the number of cell groups in the cell set configured for L1 / L2 mobility may exceed the number of available TAG IDs. Various techniques for TAG maintenance, updating and signaling are disclosed herein. In one example, a UE receives an L1 mobility cell configuration or an L2 mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes multiple cells, wherein a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with an sTAG, wherein the pTAG is associated with a first TA and the sTAG is associated with a second TA. The UE receives L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG. The pTAG / sTAG association may be updated based on the L1 signaling or the L2 signaling for communication between the UE and cells belonging to the pTAG / sTAG without the UE receiving RRC signaling (which may be time consuming as described above). Therefore, the L1 signaling or the L2 signaling may be associated with increased communication reliability. Various techniques for managing TAG IDs when the number of cell groups exceeds the number of available TAG IDs are also disclosed herein.

[0174] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is merely an illustration of the exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart may be rearranged based on design preferences. Further, some blocks may be combined or omitted. The attached method claims provide the elements of the various blocks in a sample order, but are not limited to the specific order or hierarchy provided.

[0175] 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 apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not limited to the various aspects described herein, but should be given the full scope consistent with the language claims. Unless otherwise specified, reference to an element in the singular form does not mean "one and only one", but "one or more". Terms such as "if", "when" and "while" do not mean a direct temporal relationship or reaction. That is, these phrases, such as "when ...", do not mean an immediate action in response to the occurrence of an action or during the occurrence of an action, but simply imply that if the conditions are met, the action will occur, but no specific or immediate time limit is required for the occurrence of the action. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or having advantages over other aspects. Unless otherwise specified, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, which may include multiple A, multiple B, or multiple C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination may contain one or more members of A, B, or C. A set should be interpreted as a set of elements, where the number of elements is one or more. Thus, for a set of X, X will include one or more elements. If the first device receives data from the second device or sends data to the second device, data may be directly received / sent between the first device and the second device, or indirectly received / sent between the first device and the second device through a collection of devices. All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure that are known or will later be known to a person of ordinary skill in the art are expressly incorporated herein by reference and are covered by 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. Words such as "module", "mechanism", "element", "device" cannot replace the word "component". Therefore, no claim element will be understood as a component plus function unless the element is explicitly stated using the phrase "component for..."

[0176] As used herein, the phrase "based on" should not be interpreted as referring to a closed set of information, one or more conditions, one or more factors, etc. In other words, the phrase "based on A" (where "A" can be information, a condition, a factor, etc.) should be interpreted as "based at least on A" unless specifically stated differently.

[0177] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0178] Aspect 1 is a method for wireless communication at a user equipment (UE), the method comprising: receiving a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups includes multiple cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance group (TA) and the sTAG is associated with a second TA; and receiving L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG.

[0179] Aspect 2 is a method according to aspect 1, the method further comprising: updating the second cell group to be associated with the pTAG and updating the first cell group to be associated with the sTAG based on the L1 signaling or the L2 signaling.

[0180] Aspect 3 is a method according to any one of Aspects 1 to 2, the method further comprising: receiving a timing advance group (TAG) identifier (ID) configuration via radio resource control (RRC) signaling, the timing advance group (TAG) identifier (ID) configuration comprising a first ID for the pTAG and a second ID for the sTAG.

[0181] Aspect 4 is a method according to Aspect 3, wherein the first cell group includes a first cell used as a special cell (SpCell) before receiving the L1 signaling or the L2 signaling, and wherein the second cell group includes a second cell used as a secondary cell (SCell) before receiving the L1 signaling or the L2 signaling.

[0182] Aspect 5 is a method according to Aspect 4, and the method also includes: before receiving the L1 signaling or the L2 signaling, receiving a second L1 signaling or a second L2 signaling that causes the second cell to be used as the SpCell and causes the first cell to be used as the SCell, wherein the L1 signaling or the L2 signaling associates the second cell group with the first ID used for the pTAG and associates the first cell group with the second ID used for the sTAG.

[0183] Aspect 6 is a method according to aspect 4, wherein the L1 signaling or the L2 signaling causes the second cell to be used as the SpCell and causes the first cell to be used as the SCell, wherein the L1 signaling or the L2 signaling indicates that the second cell group will be associated with the first ID used for the pTAG and the first cell group will be associated with the second ID used for the sTAG.

[0184] Aspect 7 is a method according to Aspect 4, wherein the L1 signaling or the L2 signaling enables the second cell to be used as the SpCell and the first cell to be used as the SCell, wherein based on receiving the L1 signaling or the L2 signaling, the second cell group is associated with the first ID used for the pTAG and the first cell group is associated with the second ID used for the sTAG.

[0185] Aspect 8 is a method according to any one of Aspects 3 to 7, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE) associated with a logical channel index (LCID), wherein the MAC-CE and a portion of the LCID indicate an ID for the TAG.

[0186] Aspect 9 is a method according to any one of Aspects 3 to 7, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE), wherein a portion of the MAC-CE indicates an ID for the TAG.

[0187] Aspect 10 is a method according to any one of Aspects 3 to 9, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, and the method further includes: receiving an indication of an active TAG group, wherein the active TAG group includes the first cell group, the second cell group, and a third or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent time point, wherein a fourth or more cell groups in the set of cell groups are not included in the active TAG group.

[0188] Aspect 11 is a method according to Aspect 10, wherein the first cell group, the second cell group and the third one or more cell groups included in the active TAG group are synchronized with the UE, and based on the fact that the fourth one or more cell groups are not included in the active TAG group, the fourth one or more cell groups not included in the active TAG group are not synchronized with the UE.

[0189] Aspect 12 is a method according to Aspect 11, the method also including: receiving a second L1 signaling or a second L2 signaling to modify the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding the fourth one or more cell groups to the active TAG group.

[0190] Aspect 13 is a method according to aspect 12, the method further comprising: sending one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports.

[0191] Aspect 14 is a method according to any one of Aspects 12 to 13, the method further comprising: sending a second indication indicating that the UE is predicted to communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the second indication.

[0192] Aspect 15 is a method according to any one of aspects 12 to 14, wherein the second L1 signaling or the second L2 signaling is based on one or more frequency bands associated with the set of cell groups.

[0193] Aspect 16 is a method according to Aspect 3, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the TAG ID configuration also includes a reference TAG ID associated with each of one or more cell groups in the set of cell groups.

[0194] Aspect 17 is a method according to aspect 16, wherein the TA of each of the one or more cell groups is determined based on one or more TA offsets relative to the TA associated with the reference TAG ID, wherein the one or more TA offsets are included in the TAG ID configuration.

[0195] Aspect 18 is a method according to any one of aspects 1 to 17, wherein the L1 signaling or the L2 signaling is received based on a change in location of the UE.

[0196] Aspect 19 is a method according to any one of aspects 1 to 18, the method further comprising sending data or at least one signal based on the L1 signaling or the L2 signaling.

[0197] Aspect 20 is an apparatus for wireless communication at a user equipment (UE), the apparatus comprising at least one memory and at least one processor, the at least one processor being coupled to the at least one memory and being configured, alone or in any combination, to perform a method according to any one of Aspects 1 to 18 based at least in part on information stored in the at least one memory.

[0198] Aspect 21 is an apparatus for wireless communication, the apparatus comprising means for performing a method according to any one of aspects 1 to 19.

[0199] Aspect 22 is an apparatus according to Aspect 20 or 21, the apparatus further comprising at least one of a transceiver or an antenna coupled to the at least one processor, wherein in order to receive the L1 signaling or the L2 signaling, the at least one processor is configured to receive the L1 signaling or the L2 signaling via at least one of the transceiver or the antenna.

[0200] Aspect 23 is a computer-readable medium (e.g., a non-transitory computer-readable medium) comprising computer-executable code, which, when executed by at least one processor, causes the at least one processor to perform a method according to any one of Aspects 1 to 19.

[0201] Aspect 24 is a method for wireless communication at a network entity, the method comprising: sending a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups for a user equipment (UE), wherein each cell group in the set of cell groups includes multiple cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; and sending L1 signaling or L2 signaling associating the second cell group with the pTAG and associating the first cell group with the sTAG.

[0202] Aspect 25 is a method according to aspect 24, the method further comprising: sending a timing advance group (TAG) identifier (ID) configuration via radio resource control (RRC) signaling, the timing advance group (TAG) identifier (ID) configuration comprising a first ID for the pTAG and a second ID for the sTAG.

[0203] Aspect 26 is a method according to any one of Aspects 24 to 25, wherein the first cell group includes a first cell used as a special cell (SpCell) before sending the L1 signaling or the L2 signaling, and wherein the second cell group includes a second cell used as a secondary cell (SCell) before sending the L1 signaling or the L2 signaling.

[0204] Aspect 27 is a method according to Aspect 26, the method further comprising: sending a second L1 signaling or a second L2 signaling to use the second cell as the SpCell and the first cell as the SCell before sending the L1 signaling or the L2 signaling, wherein the L1 signaling or the L2 signaling associates the second cell group with the first ID used for the pTAG and associates the first cell group with the second ID used for the sTAG.

[0205] Aspect 28 is a method according to aspect 26, wherein the L1 signaling or the L2 signaling causes the second cell to be used as the SpCell and causes the first cell to be used as the SCell, wherein the L1 signaling or the L2 signaling indicates that the second cell group will be associated with the first ID used for the pTAG and the first cell group will be associated with the second ID used for the sTAG.

[0206] Aspect 29 is a method according to Aspect 26, wherein the L1 signaling or the L2 signaling enables the second cell to be used as the SpCell and the first cell to be used as the SCell, wherein based on sending the L1 signaling or the L2 signaling, the second cell group is associated with the first ID for the pTAG and the first cell group is associated with the second ID for the sTAG.

[0207] Aspect 30 is a method according to Aspect 25, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE) associated with a logical channel index (LCID), wherein the MAC-CE and a portion of the LCID indicate an ID for the TAG.

[0208] Aspect 31 is a method according to aspect 25, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE), wherein a portion of the MAC-CE indicates an ID for the TAG.

[0209] Aspect 32 is a method according to Aspect 25, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, and the method further includes: sending an indication of an active TAG group, wherein the active TAG group includes the first cell group, the second cell group and a third one or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent time point, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group.

[0210] Aspect 33 is a method according to aspect 32, wherein the first cell group, the second cell group and the third one or more cell groups included in the active TAG group are synchronized with the UE, and based on the fact that the fourth one or more cell groups are not included in the active TAG group, the fourth one or more cell groups not included in the active TAG group are not synchronized with the UE.

[0211] Aspect 34 is a method according to aspect 33, the method also including: sending a second L1 signaling or a second L2 signaling to modify the composition of the active TAG group, wherein the modification of the composition of the active TAG group includes at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for the second time, removing the third one or more cell groups from the active TAG group for the third time, or adding the fourth one or more cell groups to the active TAG group.

[0212] Aspect 35 is a method according to aspect 34, the method further comprising: receiving one or more measurement reports, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports.

[0213] Aspect 36 is a method according to aspect 35, the method further comprising: predicting, based on the one or more measurement reports, that the UE will communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the prediction.

[0214] Aspect 37 is a method according to any one of aspects 35 to 36, the method further comprising: receiving a second indication indicating that the UE is predicted to communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the second indication.

[0215] Aspect 38 is a method according to aspect 34, wherein the second L1 signaling or the second L2 signaling is based on one or more frequency bands associated with the set of cell groups.

[0216] Aspect 39 is a method according to Aspect 25, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the TAG ID configuration also includes a reference TAG ID associated with each of one or more cell groups in the set of cell groups.

[0217] Aspect 40 is a method according to aspect 39, wherein the TA of each of the one or more cell groups is determined based on one or more TA offsets relative to the TA associated with the reference TAG ID, wherein the one or more TA offsets are included in the TAG ID configuration.

[0218] Aspect 41 is a method according to any one of aspects 24 to 40, wherein the L1 signaling or the L2 signaling is sent based on a change in location of the UE.

[0219] Aspect 42 is a method according to any one of aspects 24 to 41, the method further comprising receiving data or at least one signal based on the L1 signaling or the L2 signaling.

[0220] Aspect 43 is an apparatus for wireless communication at a network entity, the apparatus comprising at least one memory and at least one processor, the at least one processor being coupled to the at least one memory and being configured, alone or in any combination, to perform a method according to any one of Aspects 24 to 42 based at least in part on information stored in the at least one memory.

[0221] Aspect 44 is an apparatus for wireless communication, the apparatus comprising means for performing a method according to any one of aspects 24 to 42.

[0222] Aspect 45 is an apparatus according to Aspect 43 or 44, the apparatus further comprising at least one of a transceiver or an antenna coupled to the at least one processor, wherein in order to send the L1 signaling or the L2 signaling, the at least one processor is configured to send the L1 signaling or the L2 signaling via at least one of the transceiver or the antenna.

[0223] Aspect 46 is a computer-readable medium (e.g., a non-transitory computer-readable medium) comprising computer-executable code, which, when executed by at least one processor, causes the at least one processor to perform a method according to any one of aspects 24 to 42.

Claims

1. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: at least one memory; and at least one processor coupled to the at least one memory and, based at least in part on information stored in the at least one memory, the at least one processor configured, alone or in any combination, to: receiving a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups comprises a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; as well as L1 signaling or L2 signaling is received to associate the second cell group with the pTAG and the first cell group with the sTAG.

2. The apparatus of claim 1 , wherein the at least one processor, alone or in any combination, is further configured to: The second cell group is updated to be associated with the pTAG and the first cell group is updated to be associated with the sTAG based on the L1 signaling or the L2 signaling.

3. The apparatus of claim 1 , wherein the at least one processor, alone or in any combination, is further configured to: A timing advance group (TAG) identifier (ID) configuration is received via radio resource control (RRC) signaling, the timing advance group (TAG) identifier (ID) configuration including a first ID for the pTAG and a second ID for the sTAG.

4. The apparatus according to claim 3, wherein the first cell group includes a first cell used as a special cell (SpCell) before the reception of the L1 signaling or the L2 signaling, and wherein the second cell group includes a second cell used as a secondary cell (SCell) before the reception of the L1 signaling or the L2 signaling.

5. The apparatus of claim 4, wherein the at least one processor, alone or in any combination, is further configured to: A second L1 signaling or a second L2 signaling is received before the receiving of the L1 signaling or the L2 signaling, which causes the second cell to function as the SpCell and causes the first cell to function as the SCell, wherein the L1 signaling or the L2 signaling associates the second cell group with the first ID for the pTAG and associates the first cell group with the second ID for the sTAG.

6. The apparatus according to claim 4, wherein the L1 signaling or the L2 signaling causes the second cell to be used as the SpCell and causes the first cell to be used as the SCell, wherein the L1 signaling or the L2 signaling indicates that the second cell group will be associated with the first ID for the pTAG and the first cell group will be associated with the second ID for the sTAG.

7. The apparatus of claim 4, wherein the L1 signaling or the L2 signaling causes the second cell to function as the SpCell and the first cell to function as the SCell, wherein based on the reception of the L1 signaling or the L2 signaling, the second cell group is associated with the first ID for the pTAG and the first cell group is associated with the second ID for the sTAG.

8. An apparatus according to claim 3, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE) associated with a logical channel index (LCID), wherein the MAC-CE and a portion of the LCID indicate an ID for the TAG.

9. The apparatus of claim 3, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling comprises a medium access control (MAC) control element (MAC-CE), wherein a portion of the MAC-CE indicates an ID for the TAG.

10. The apparatus of claim 3, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the at least one processor, alone or in any combination, is further configured to: Receive an indication of an active TAG group, wherein the active TAG group includes the first cell group, the second cell group, and a third one or more cell groups in the set of cell groups via which the UE is predicted to communicate at a first subsequent time point, wherein a fourth one or more cell groups in the set of cell groups are not included in the active TAG group.

11. The apparatus according to claim 10, wherein the first cell group, the second cell group and the third one or more cell groups included in the active TAG group are synchronized with the UE, and wherein based on the fact that the fourth one or more cell groups are not included in the active TAG group, the fourth one or more cell groups not included in the active TAG group are not synchronized with the UE.

12. The apparatus of claim 11, wherein the at least one processor, alone or in any combination, is further configured to: receiving a second L1 signaling or a second L2 signaling for modifying the composition of the active TAG group, wherein the modification of the composition of the active TAG group comprises at least one of the following: removing the first cell group from the active TAG group for the first time, removing the second cell group from the active TAG group for a second time, removing the third one or more cell groups from the active TAG group for a third time, or The fourth one or more cell groups are added to the active TAG group.

13. The apparatus of claim 12, wherein the at least one processor, alone or in any combination, is further configured to: One or more measurement reports are sent, wherein the second L1 signaling or the second L2 signaling is based on the one or more measurement reports.

14. The apparatus of claim 12, wherein the at least one processor, alone or in any combination, is further configured to: A second indication is sent indicating that the UE is predicted to communicate via the fourth one or more cell groups at a second subsequent time point, wherein the second L1 signaling or the second L2 signaling is based on the second indication. 15 . The apparatus of claim 12 , wherein the second L1 signaling or the second L2 signaling is based on one or more frequency bands associated with the set of cell groups.

16. The apparatus of claim 3, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for TAGs, wherein the TAG ID configuration further comprises a reference TAG ID associated with each of one or more cell groups in the set of cell groups.

17. The apparatus of claim 16, wherein the TA of each of the one or more cell groups is determined based on one or more TA offsets relative to a TA associated with the reference TAG ID, wherein the one or more TA offsets are included in the TAG ID configuration.

18. The apparatus of claim 1, wherein the at least one processor, alone or in any combination, is further configured to: Data or at least one signal is sent based on the L1 signaling or the L2 signaling.

19. The apparatus of claim 1, further comprising at least one of a transceiver or an antenna coupled to the at least one processor, wherein in order to receive the L1 signaling or the L2 signaling, the at least one processor is configured, alone or in any combination, to receive the L1 signaling or the L2 signaling via at least one of the transceiver or the antenna.

20. An apparatus for wireless communication at a network entity, the apparatus comprising: at least one memory; and at least one processor coupled to the at least one memory and, based at least in part on information stored in the at least one memory, the at least one processor configured, alone or in any combination, to: transmitting a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups of a user equipment (UE), wherein each cell group in the set of cell groups comprises a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; as well as L1 signaling or L2 signaling is sent to associate the second cell group with the pTAG and the first cell group with the sTAG.

21. The apparatus of claim 20, wherein the at least one processor, alone or in any combination, is further configured to: A timing advance group (TAG) identifier (ID) configuration is transmitted via radio resource control (RRC) signaling, the timing advance group (TAG) identifier (ID) configuration including a first ID for the pTAG and a second ID for the sTAG.

22. The apparatus according to claim 21, wherein the first cell group includes a first cell used as a special cell (SpCell) before the transmission of the L1 signaling or the L2 signaling, and wherein the second cell group includes a second cell used as a secondary cell (SCell) before the transmission of the L1 signaling or the L2 signaling.

23. The apparatus of claim 22, wherein the at least one processor, alone or in any combination, is further configured to: A second L1 signaling or a second L2 signaling is sent before the sending of the L1 signaling or the L2 signaling to cause the second cell to function as the SpCell and the first cell to function as the SCell, wherein the L1 signaling or the L2 signaling associates the second cell group with the first ID for the pTAG and associates the first cell group with the second ID for the sTAG.

24. The apparatus of claim 22, wherein the L1 signaling or the L2 signaling causes the second cell to function as the SpCell and the first cell to function as the SCell, wherein the L1 signaling or the L2 signaling indicates that the second cell group will be associated with the first ID for the pTAG and the first cell group will be associated with the second ID for the sTAG.

25. The apparatus of claim 22, wherein the L1 signaling or the L2 signaling causes the second cell to function as the SpCell and causes the first cell to function as the SCell, wherein based on the sending of the L1 signaling or the L2 signaling, the second cell group is associated with the first ID for the pTAG and the first cell group is associated with the second ID for the sTAG.

26. An apparatus according to claim 21, wherein a first number of cell groups in the set of cell groups is greater than a second number of available IDs for a TAG, wherein the TAG ID configuration configures a third number of IDs for the TAG, the third number being greater than the second number, wherein the L2 signaling includes a medium access control (MAC) control element (MAC-CE) associated with a logical channel index (LCID), wherein the MAC-CE and a portion of the LCID indicate an ID for the TAG.

27. The apparatus of claim 21, wherein the at least one processor, alone or in any combination, is further configured to: Data or at least one signal is received based on the L1 signaling or the L2 signaling.

28. The apparatus of claim 20, further comprising at least one of a transceiver or an antenna coupled to the at least one processor, wherein to send the L1 signaling or the L2 signaling, the at least one processor is configured, alone or in any combination, to send the L1 signaling or the L2 signaling via at least one of the transceiver or the antenna.

29. A method of wireless communication at a user equipment (UE), the method comprising: receiving a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups, wherein each cell group in the set of cell groups comprises a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; as well as L1 signaling or L2 signaling is received to associate the second cell group with the pTAG and the first cell group with the sTAG.

30. A method for wireless communication at a network entity, the method comprising: transmitting a layer 1 (L1) mobility cell configuration or a layer 2 (L2) mobility cell configuration for a set of cell groups of a user equipment (UE), wherein each cell group in the set of cell groups comprises a plurality of cells, wherein a first cell group in the set of cell groups is associated with a primary timing advance group (pTAG) and a second cell group in the set of cell groups is associated with a secondary timing advance group (sTAG), wherein the pTAG is associated with a first timing advance (TA) and the sTAG is associated with a second TA; as well as L1 signaling or L2 signaling is sent to associate the second cell group with the pTAG and the first cell group with the sTAG.

Images