User equipment assisted uplink synchronization for inter-cell mobility

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may monitor reference signals from a first reference cell and a second deactivated cell, and the UE may report a timing difference between a first timing advance for the first cell and a second timing advance for the second cell. In some cases, the UE may periodically report the timing difference, and in other cases, the UE may aperiodically report the timing difference. When a network entity receives the timing difference, the network entity may determine the second timing difference for the UE to use to communicate with the second cell. Then, when the second cell is activated for communicating with the UE, the network entity may signal the second timing difference to the UE, and the UE may communicate with the second cell using the second timing advance.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 17 / 857,738, filed by ZHOU et al. on July 5, 2022, entitled “USER EQUIPMENT ASSISTED UPLINK SYNCHRONIZATION FOR INTER-CELL MOBILITY,” which is assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety. Technical Field

[0003] The following relates to wireless communications including user equipment assisted uplink synchronization for inter-cell mobility. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

[0005] A wireless multiple access communication system may include one or more base stations, each of which supports wireless communication for a communication device, which may be referred to as a user equipment (UE). In some wireless communication systems, a network entity may configure a set of cells for communicating with a UE. Improved techniques for supporting communication between a UE and one or more cells in the configured set of cells may be desired. Summary of the invention

[0006] The described technology relates to improved methods, systems, devices and apparatuses that support user equipment (UE) assisted uplink synchronization for inter-cell mobility. The UE can monitor reference signals from a first reference cell and a second deactivated cell, and the UE can report a timing difference between a first timing advance of the first cell and a second timing advance of the second cell. In some cases, the UE can report the timing difference periodically, and in other cases, the UE can report the timing difference aperiodically. When a network entity receives the timing difference, the network entity can determine a second timing advance for the UE to use to communicate with the second cell. Then, when the second cell is activated for communication with the UE, the network entity can signal the second timing advance to the UE, and the UE can use the second timing advance to communicate with the second cell.

[0007] A method for wireless communication at a user equipment (UE) is described. The method may include: receiving an indication of a set of cells configured for communication with the UE; receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell and the second cell is deactivated; and sending an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0008] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: receive an indication of a set of cells configured for communication with the UE; receive a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated; and send an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include: means for receiving an indication of a set of cells configured for communication with the UE; means for receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell and the second cell is deactivated; and means for sending an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0010] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions that can be executed by a processor to: receive an indication of a set of cells configured for communication with the UE; receive a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated; and send an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving an indication that the second cell may be activated; receiving an indication of a second timing advance for communicating with the second cell based on sending the timing difference; and communicating with the second cell using the second timing advance.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the indication of the timing difference may include operations, features, components, or instructions for sending a periodic sending including the indication of the timing difference.

[0013] Some examples of the methods, apparatuses, and non-transitory computer readable media described herein may further include operations, features, components, or instructions for receiving an indication of a periodicity for transmitting a periodic transmission including an indication of a timing difference.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the indication of the timing difference may include operations, features, components, or instructions for sending a non-periodic transmission including the indication of the timing difference.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for identifying one or more trigger conditions for sending the timing difference, wherein sending the non-periodic transmission may be based on at least one of the one or more trigger conditions being satisfied.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

[0017] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an indication of the one or more triggering conditions for sending the timing difference.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for receiving a request to send the timing difference, wherein sending the aperiodic transmission may be based on receiving the request.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a set of multiple timing differences between a timing advance for communicating with the first cell and a timing advance for communicating with the second cell, the set of multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an indication that the first cell may be the reference cell, wherein the first cell may be selected as the reference cell based on cell quality, cell functionality, or a combination thereof.

[0021] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving an indication of a set of multiple configurations for the UE to use to send the timing difference; and receiving a control message indicating a configuration in the set of multiple configurations for the UE to use to send the timing difference, wherein sending the indication of the timing difference may be based on the configuration.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the timing difference between the first timing advance and the second timing advance can be based on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0023] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication of the timing difference may be sent in a medium access control control element or in a measurement report in uplink control information.

[0024] A method for wireless communication at a network entity is described. The method may include: sending an indication of a set of cells configured for communication with a UE; sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; and receiving an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0025] An apparatus for wireless communication at a network entity is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to: send an indication of a set of cells configured for communication with a UE; send a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; and receive an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0026] Another apparatus for wireless communication at a network entity is described. The apparatus may include: means for sending an indication of a set of cells configured for communication with a UE; means for sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; and means for receiving an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0027] A non-transitory computer-readable medium storing code for wireless communication at a network entity is described. The code may include instructions executable by a processor to: send an indication of a set of cells configured for communication with a UE; send a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; and receive an indication of a timing difference between a first timing advance for communication with the first cell and a second timing advance for communication with the second cell.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: sending an indication that the second cell may be activated; and sending an indication of the second timing advance for communicating with the second cell based on receiving the timing difference.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the indication of the timing difference may include operations, features, components, or instructions for receiving a periodic transmission including the indication of the timing difference.

[0030] Some examples of the methods, apparatuses, and non-transitory computer readable media described herein may also include operations, features, components, or instructions for sending an indication of periodicity of periodic transmissions from the UE including an indication of a timing difference.

[0031] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the indication of the timing difference may include operations, features, components, or instructions for receiving a non-periodic transmission including the indication of the timing difference.

[0032] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an indication of one or more trigger conditions for the UE to send the timing difference, wherein receiving the non-periodic transmission may be based on at least one of the one or more trigger conditions being satisfied.

[0033] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

[0034] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a request for the UE to send the timing difference, wherein receiving the aperiodic transmission may be based on sending the request.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a set of multiple timing differences between a timing advance for communicating with the first cell and a timing advance for communicating with the second cell, the set of multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0036] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an indication that the first cell may be the reference cell, wherein the first cell may be selected as the reference cell based on cell quality, cell functionality, or a combination thereof.

[0037] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: sending an indication of a set of multiple configurations for the UE to use to send the timing difference; and sending a control message indicating a configuration in the set of multiple configurations for the UE to use to send the timing difference, wherein receiving the indication of the timing difference may be based on the configuration.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the timing difference between the first timing advance and the second timing advance can be based on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication of the timing difference may be received in a measurement report in a medium access control control element or in uplink control information. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 An example of a wireless communication system supporting user equipment (UE) assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is illustrated.

[0041] Figure 2 An example of inter-cell mobility according to one or more aspects of the present disclosure is illustrated.

[0042] Figure 3 An example of a wireless communication system supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is illustrated.

[0043] Figure 4 An example of a process flow for supporting UE-assisted uplink synchronization for inter-cell mobility in accordance with one or more aspects of the present disclosure is illustrated.

[0044] Figure 5 and Figure 6 A block diagram of an apparatus supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown.

[0045] Figure 7 A block diagram of a communications manager supporting UE-assisted uplink synchronization for inter-cell mobility is shown in accordance with one or more aspects of the present disclosure.

[0046] Figure 8A diagram of a system including a device supporting UE-assisted uplink synchronization for inter-cell mobility is shown in accordance with one or more aspects of the present disclosure.

[0047] Fig. 9 and Fig.10 A block diagram of an apparatus supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown.

[0048] Fig.11 A block diagram of a communications manager supporting UE-assisted uplink synchronization for inter-cell mobility is shown in accordance with one or more aspects of the present disclosure.

[0049] Fig.12 A diagram of a system including a device supporting UE-assisted uplink synchronization for inter-cell mobility is shown in accordance with one or more aspects of the present disclosure.

[0050] Fig.13 and Fig.14 A flow chart illustrating a method of supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0051] In some wireless communication systems, a network entity may configure a set of cells for communicating with a user equipment (UE). The configured set of cells may include activated cells and deactivated cells. The UE may communicate with an activated cell in the configured set of cells, and the deactivated cell may be subsequently activated for communication with the UE. The network entity may use dynamic signaling (e.g., layer one (L1) or layer two (L2) signaling) to activate and deactivate cells in the configured set of cells to allow the UE to communicate with different subsets of the configured set of cells.

[0052] When a cell is activated, the UE may perform a random access channel (RACH) procedure to synchronize timing with the cell, and the UE may communicate with the cell after uplink synchronization. For example, the UE may identify a timing advance for communicating with the cell in a RACH procedure, and the UE may communicate with the cell using the timing advance. However, in some cases, when a cell is activated for communication with the UE, the UE may experience increased latency and power consumption by performing the RACH procedure. This latency and power consumption may eliminate the benefits of dynamic activation of the cell, which may be detrimental to the wireless communication system.

[0053] As described herein, a wireless communication system may support efficient techniques for facilitating uplink synchronization with a cell at a UE when the cell is activated for communication with the UE. The UE may monitor reference signals from a first reference cell and a second deactivated cell, and the UE may report a timing difference between a first timing advance of the first cell and a second timing advance of the second cell. In some cases, the UE may report the timing difference periodically, and in other cases, the UE may report the timing difference aperiodically (e.g., in response to a request or based on satisfying one or more trigger conditions). When a network entity receives the timing difference, the network entity may determine a second timing advance for the UE to use to communicate with the second cell. Then, when the second cell is activated for communication with the UE, the network entity may signal the UE the second timing advance, and the UE may communicate with the second cell using the second timing advance.

[0054] Aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow diagrams relating to UE-assisted uplink synchronization for inter-cell mobility.

[0055] Figure 1 An example of a wireless communication system 100 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, a new radio (NR) network, or a network operating according to other systems and radio technologies (including future systems and radio technologies not explicitly mentioned herein).

[0056] The network entities 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may include devices in different forms or with different capabilities. In various examples, the network entities 105 may be referred to as network elements, mobility elements, radio access network (RAN) nodes, or network equipment, among other names. In some examples, the network entities 105 and the UE 115 may communicate wirelessly via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, the network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) within which the UE 115 and the network entity 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area within which the network entity 105 and the UE 115 may support signal communications according to one or more radio access technologies (RATs).

[0057] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be devices in different forms or with different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of supporting communication with various types of devices (such as Figure 1 Communicate with other UEs 115 or network entities 105) as shown.

[0058] As described herein, a node of the wireless communication system 100 (which may be referred to as a network node or a wireless node) may be a network entity 105 (e.g., any network entity described herein), a UE 115 (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, the node may be a UE 115. As another example, the node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different relative to these examples. Similarly, references to UE 115, network entity 105, apparatus, device, computing system, etc. may include disclosure of UE 115, network entity 105, apparatus, device, computing system, etc. as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that the first node is configured to receive information from the second node.

[0059] In some examples, the network entities 105 may communicate with the core network 130, or with each other, or both. For example, the network entities 105 may communicate with the core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, the network entities 105 may communicate with each other directly (e.g., directly between the network entities 105) or indirectly (e.g., via the core network 130) via the backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols). In some examples, the network entities 105 may communicate with each other via midhaul communication links 162 (e.g., according to a midhaul interface protocol) or fronthaul communication links 168 (e.g., according to a fronthaul interface protocol) or any combination thereof. The backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 may be or include one or more wired links (e.g., electrical links, optical fiber links), one or more wireless links (e.g., radio links, wireless optical links), etc. or various combinations thereof. UE 115 may communicate with core network 130 via communication link 155 .

[0060] One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a transceiver base station, a radio base station, an NR base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next-generation Node B, or a giga-Node B (any of which may be referred to as a gNB), a 5G NB, a next-generation eNB (ng-eNB), a home Node B, a home evolved Node B, or other suitable terms). In some examples, the network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, stand-alone) base station architecture, which may be configured to utilize a protocol stack physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as a base station 140).

[0061] In some examples, the network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) that may be configured to utilize a protocol stack that is physically or logically distributed between two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, the network entity 105 may include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC (near RT RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) 180 system, or any combination thereof. The RU 170 may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmit receive point (TRP). One or more components of the network entity 105 in the decomposed RAN architecture may be co-located, or one or more components of the network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 of the decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0062] The functional split between CU 160, DU 165, and RU 170 is flexible and can support different functionalities, depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a functional split of a protocol stack can be employed between CU 160 and DU 165, such that CU 160 can support one or more layers of a protocol stack and DU 165 can support one or more different layers of a protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., layer 3 (L3), layer 2 (L2)) functionality and signaling (e.g., radio resource control (RRC), service data adaptation protocol (SDAP), packet data convergence protocol (PDCP)). The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally or alternatively, a functional split of the protocol stack may be employed between the DU 165 and the RU 170, such that the DU 165 may support one or more layers of the protocol stack, and the RU 170 may support one or more different layers of the protocol stack. The DU 165 may support one or more different cells (e.g., via one or more RUs 170). In some cases, the functional split between CU 160 and DU 165 or between DU 165 and RU 170 can be within the protocol layer (e.g., some functions of the protocol layer can be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer are performed by different ones of CU 160, DU 165, or RU 170). CU 160 can be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. CU 160 can be connected to one or more DUs 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and DU 165 can be connected to one or more RUs 170 via fronthaul communication links 168 (e.g., open fronthaul (FH) interface). In some examples, midhaul communication link 162 or fronthaul communication link 168 may be implemented based on interfaces (eg, channels) between layers of a protocol stack supported by respective network entities 105 that communicate via these communication links.

[0063] In some wireless communication systems (e.g., wireless communication system 100), infrastructure and spectrum resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB nodes 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as donor entities or IAB donors. One or more DUs 165 or one or more RUs 170 may be controlled in part by one or more CUs 160 associated with a donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB nodes 104) via supported access and backhaul links (e.g., backhaul communication links 120). The IAB node 104 may include an IAB mobile termination (IAB-MT) controlled (e.g., scheduled) by a DU 165 of a coupled IAB donor. The IAB-MT may include a collection of independent antennas for relaying communications with the UE 115, or may share the same antenna of the IAB node 104 (e.g., of the RU 170) for access via the DU 165 of the IAB node 104 (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, the IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of the IAB node 104) may be configured to operate according to the techniques described herein.

[0064] Where the techniques described herein are applied in the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture may be configured to support cell management for inter-cell mobility as described herein. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., an IAB node 104, a DU 165, a CU 160, a RU 170, a RIC 175, a SMO 180).

[0065] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or may be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0066] The UE 115 described herein may be capable of communicating with various types of devices such as other UEs 115 which may sometimes act as relays, as well as network entities 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 shown.

[0067] The UE 115 and the network entity 105 may wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" may refer to a collection of RF spectrum resources having a physical layer structure defined for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of an RF spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communications with the UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers. Communication between the network entity 105 and other devices may refer to communication between a device and any portion (e.g., entity, sub-entity) of the network entity 105. For example, the terms "send," "receive," or "communicate" when referring to the network entity 105 may refer to any portion of the network entity 105 (e.g., base station 140, CU 160, DU 165, RU 170) of the RAN communicating with another device (e.g., directly or via one or more other network entities 105).

[0068] In some examples, such as in a carrier aggregation configuration, a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute RF Channel Number (EARFCN)) and may be identified based on a channel raster for discovery by UE 115. A carrier may operate in a standalone mode, in which case initial acquisition and connection may be performed by UE 115 via the carrier, or a carrier may operate in a non-standalone mode, in which case the connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0069] The communication link 125 shown in the wireless communication system 100 may include downlink transmissions (e.g., forward link transmissions) from the network entity 105 to the UE 115 (e.g., in a physical downlink shared channel (PDSCH) or a physical downlink control channel (PDCCH)), uplink transmissions (e.g., return link transmissions) from the UE 115 to the network entity 105 (e.g., in a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH)), or both, as well as other transmission configurations. A carrier may carry either downlink communications or uplink communications (e.g., in FDD mode), or may be configured to carry both downlink communications and uplink communications (e.g., in TDD mode).

[0070] A carrier may be associated with a particular bandwidth of the RF spectrum, and in some examples, the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a set of bandwidths (e.g., 1.4 megahertz (MHz), 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz) of a carrier of a particular radio access technology. A device (e.g., a network entity 105, a UE 115, or both) of the wireless communication system 100 may have a hardware configuration that supports communications using a particular carrier bandwidth, or may be capable of being configured to support communications using one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a network entity 105 or a UE 115 that supports concurrent communications using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate using a portion (e.g., a subband, a BWP) or all of a carrier bandwidth.

[0071] The signal waveform transmitted via the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and the subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both), so that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high order modulation scheme may correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communication with UE 115.

[0072] One or more parameter sets for a carrier may be supported, and the parameter sets may include subcarrier spacing (Δf) and cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter sets. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications for a UE 115 may be constrained to one or more active BWPs.

[0073] The time interval for the network entity 105 or the UE 115 may be expressed in multiples of a basic time unit, which may be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the supported subcarrier spacing, and N f The supported discrete Fourier transform (DFT) size may be indicated. The time intervals of the communication resources may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0074] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a certain number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a certain number of symbol periods (e.g., depending on the length of the cyclic prefix appended in front of each symbol period). In some wireless communication systems 100, the time slot may be further divided into multiple micro time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0075] A subframe, a time slot, a mini-time slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0076] Physical channels may be multiplexed according to various techniques in order to communicate using a carrier. For example, physical control channels and physical data channels may be multiplexed using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique to signal via a downlink carrier. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a set of symbol periods and may extend across a system bandwidth of a carrier or a subset of that system bandwidth. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more UEs in UE 115 may monitor or search a control region to obtain control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to a plurality of UEs 115 , and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0077] The network entity 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hot spots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with the network entity 105 (e.g., using a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other identifier) ​​used to distinguish adjacent cells. In some examples, a cell may also refer to a coverage area 110 or a portion of a coverage area 110 (e.g., a sector) on which a logical communication entity operates. Depending on various factors such as the capabilities of the network entity 105, such cells may range from smaller areas (e.g., structures, subsets of structures) to larger areas. For example, a cell may be or may include a building, a subset of a building, or an external space between or overlapping coverage areas 110, and the like.

[0078] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have service subscriptions with a network provider that supports the macro cell. A small cell may be associated with a lower power network entity 105 (e.g., a lower power base station 140) (compared to a macro cell), and the small cell may operate using the same or different (e.g., licensed, unlicensed) frequency band as the macro cell. A small cell may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). A network entity 105 may support one or more cells, and may also support communication via one or more cells (e.g., with one or more UEs 115) using one or more component carriers.

[0079] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access to different types of devices. The UE 115 may be configured with a primary cell (PCell) and one or more secondary cells (SCells) to communicate with. For example, if the UE 115 is configured for dual connectivity (DC) or carrier aggregation (CA), the UE 115 may communicate with the PCell and one or more SCells. The UE 115 may use the PCell for initial access to the network (e.g., initial access to a primary cell group (MCG)) and other communications, and the UE 115 may use one or more SCells for supplementary communications. In some cases, the UE 115 may be configured with a primary secondary cell (PSCell) that the UE 115 may use for initial access to one or more SCells (e.g., initial access to a secondary cell group (SCG)). A PCell or a PSCell (primary cell of a SCG) may be referred to as a special cell (SpCell). The SpCell configuration of the MCG may correspond to the PCell configuration, and the SpCell configuration of the SCG may correspond to the PSCell configuration.

[0080] In some examples, the network entities 105 (e.g., base stations 140, RUs 170) may be mobile and thus provide communication coverage for mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 use the same or different radio access technologies to provide coverage for various coverage areas 110.

[0081] The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, the network entities 105 (e.g., base stations 140) may have similar frame timing, and transmissions from different network entities 105 may be approximately aligned in time. For asynchronous operation, the network entities 105 may have different frame timing, and in some examples, transmissions from different network entities 105 may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0082] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a network entity 105 (e.g., base station 140) without human intervention. In some examples, M2M communication or MTC may include communication from devices with integrated sensors or meters to measure or capture information and relay such information to a central server or application that uses the information or presents the information to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, wildlife monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0083] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception but does not transmit and receive concurrently). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UE 115 include entering a power saving deep sleep mode when not engaged in active communications, operating using limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a defined portion or range (e.g., a subcarrier or resource block (RB) set) within a carrier, within a guard band of a carrier, or outside a carrier.

[0084] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC). UE 115 can be designed to support ultra-reliable, low-latency or critical functions. Ultra-reliable communication can include private communication or group communication, and can be supported by one or more services (such as push-to-talk, video or data). Support for ultra-reliable, low-latency functions can include prioritization of services, and such services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency and ultra-reliable low-latency can be used interchangeably in this article.

[0085] In some examples, the UE 115 may be configured to support communication directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., according to a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs 115 in a group that are performing D2D communication may be within a coverage area 110 of a network entity 105 (e.g., a base station 140, a RU 170), which may support aspects of such D2D communication configured (e.g., scheduled) by the network entity 105. In some examples, one or more UEs 115 in such a group may be outside of the coverage area 110 of the network entity 105, or may otherwise be unable or not configured to receive transmissions from the network entity 105. In some examples, a group of UEs 115 communicating via D2D communication may support a one-to-many (1:M) system, in which each UE 115 transmits to each of the other UEs 115 in the group. In some examples, network entity 105 may facilitate scheduling of resources for D2D communications. In some other examples, D2D communications may be performed between UEs 115 without involving network entity 105.

[0086] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these items. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units), or communicate with the network via one or more network nodes (e.g., network entity 105, base station 140, RU 170) using vehicle-to-network (V2N) communication, or both.

[0087] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity for managing access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity for routing packets or interconnecting to an external network (e.g., a serving gateway (S-GW)), a packet data network (PDN) gateway (P-GW) or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management of UE 115 served by a network entity 105 (e.g., a base station 140) associated with the core network 130. User IP packets may be delivered through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the IP service 150 of one or more network operators. IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0088] The wireless communication system 100 can operate using one or more frequency bands that can be in the range of 300 megahertz (MHz) to 300 kilohertz (GHz). Generally speaking, the area from 300MHz to 3GHz is called the ultra-high frequency (UHF) area or decimeter band because the wavelength range is about one decimeter to one meter long. UHF waves may be blocked or redirected by buildings and environmental features (which may be referred to as clusters), but these waves may be sufficient to penetrate the structure so that the macrocell provides services to the UE 115 located indoors. Compared with the communication of the lower frequencies and longer wavelengths of the high frequency (HF) or very high frequency (VHF) parts of the spectrum below 300MHz, the communication using UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers).

[0089] The wireless communication system 100 may also operate using a super high frequency (SHF) region, which may be in the range of 3 GHz to 30 GHz (also known as a centimeter band), or an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as a millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between a UE 115 and a network entity 105 (e.g., a base station 140, a RU 170), and the EHF antennas of the corresponding devices may be smaller and closer together than UHF antennas. In some examples, such techniques may facilitate the use of antenna arrays within a device. However, the propagation of EHF transmissions may be affected by even greater attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the use of frequency bands specified across these frequency regions may vary by country or regulatory agency.

[0090] The wireless communication system 100 can utilize licensed and unlicensed RF spectrum bands. For example, the wireless communication system 100 can use unlicensed bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band) to employ license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology. When operating using unlicensed RF spectrum bands, devices such as network entity 105 and UE 115 can employ carrier sensing for conflict detection and avoidance. In some examples, operations performed using unlicensed bands can be based on carrier aggregation configuration (e.g., LAA) in combination with component carriers operating using licensed bands. Operations performed using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0091] The network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas, which may be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of the network entity 105 or UE 115 may be located in one or more antenna arrays or antenna panels, which may support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly such as an antenna tower. In some examples, antennas or antenna arrays associated with the network entity 105 may be located at different geographical locations. The network entity 105 may include an antenna array having a collection of multiple rows and columns of antenna ports that the network entity 105 may use to support beamforming for communications with the UE 115. Similarly, the UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals sent via the antenna ports.

[0092] The network entity 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by sending or receiving multiple signals via different spatial layers. Such technology may be referred to as spatial multiplexing. Multiple signals may be, for example, sent by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technologies include single-user MIMO (SU-MIMO), for which multiple spatial layers are sent to the same receiving device; and multi-user MIMO (MU-MIMO), for which multiple spatial layers are sent to multiple devices.

[0093] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or direct an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals conveyed via antenna elements of an antenna array so that some signals propagating in a particular direction relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals conveyed via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each of these antenna elements may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device or relative to some other direction).

[0094] The wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer or PDCP layer can be IP-based. The RLC layer can perform packet segmentation and reorganization to communicate via logical channels. The MAC layer can perform priority processing and multiplexing of logical channels into transport channels. The MAC layer can also implement error detection technology, error correction technology, or both to support retransmission to improve link efficiency. In the control plane, the RRC layer can provide the establishment, configuration, and maintenance of the RRC connection of the radio bearer that supports user plane data between the UE115 and the network entity 105 or the core network 130. The PHY layer can map the transport channel to the physical channel.

[0095] In the wireless communication system 100, the network entity 105 may configure a set of cells for communicating with the UE 115. The network entity 105 may be connected to at least one cell in the set of cells or support communication via at least one cell in the set of cells, and the network entity 105 may configure the set of cells to the UE 115 via the at least one cell. The configured set of cells may include activated cells and deactivated cells. The UE 115 may communicate with the activated cells in the configured set of cells, and then may activate the deactivated cells for communication with the UE 115 (e.g., when appropriate). The network entity 105 may activate and deactivate the cells in the configured set of cells using dynamic signaling (e.g., L1 or L2 signaling, such as downlink control information (DCI) messages or MAC control elements (MAC-CEs)) to maximize throughput (e.g., by allowing the UE 115 to communicate with an optimal subset of the configured set of cells). Activating and deactivating cells in a configured set of cells using dynamic signaling may be referred to as L1 / L2 based inter-cell mobility.

[0096] The wireless communication system 100 may support technologies for L1 / L2-based inter-cell mobility. For example, the wireless communication system 100 may support the configuration and maintenance of multiple candidate cells in a configured set of cells to allow the configuration of the candidate cells to be quickly applied. In addition, the wireless communication system 100 may support a dynamic switching mechanism between candidate serving cells (e.g., including SpCells and SCells) for potentially applicable scenarios based on L 1 / L2 signaling. The wireless communication system 100 may also support L1 enhancements for inter-cell beam management, including L1 measurements and reports and beam indications. The wireless communication system 100 may also support timing advance management and CU-DU interface signaling to support L1 / L2 mobility (e.g., if appropriate). In some examples, frequency range two (FR2) specific enhancements (e.g., if any) may not be excluded.

[0097] In addition, the described technology can provide the design and enhancement of L1 / L2-based inter-cell mobility. The procedures for L1 / L2-based inter-cell mobility can be applicable to multiple scenarios. In one example, L1 / L2-based inter-cell mobility can be used for independent, CA or NR-DC situations that support service cell changes within the configured authorization. In another example, L1 / L2-based inter-cell mobility can be used for intra-DU situations or intra-CU and inter-DU situations (for example, applicable to independent and CA, where no new RAN interface can be expected). In another example, L1 / L2-based inter-cell mobility can be used for both intra-frequency communication and inter-frequency communication. In another example, L1 / L2-based inter-cell mobility can be used for communication in both frequency range one (FR1) and frequency range two (FR2). In another example, L1 / L2-based inter-cell mobility can be used to communicate with source cells and target cells that can be synchronous or asynchronous.

[0098] Figure 2 An example of inter-cell mobility 200 according to one or more aspects of the present disclosure is illustrated. A UE 115-a may be configured with a set of cells (e.g., a configured cell set 205) for inter-cell mobility (e.g., L1 / L2 mobility). The network entity 105 may configure the set of cells using RRC signaling. In some examples, there may be one or more cells 210 outside the configured cell set 205. The cells in the configured cell set 205 may be further characterized as activated cells 215 and deactivated cells 220 (e.g., including SpCe; and SCell). The activated cell set may correspond to a group of cells that can be easily used for data and control information transmission. For example, for cells in the activated cell set, control channels may be monitored, synchronization may be maintained, or timing advance may be maintained. The deactivated cell set may correspond to a group of cells that are not activated but can be quickly activated by L1 / L2 signaling. For example, for deactivated cells, control channels may not be monitored, synchronization may not be maintained, or timing advance may not be maintained. UE 115-a may perform measurements (e.g., periodically according to configuration) on cells in the configured cell set 205 for fast L1 / L2 mobility handover. The cells in the configured cell set 205 may belong to (e.g., supported by or used for communications by) the same network entity 105 (e.g., one DU) or different network entities 105 (e.g., multiple DUs). The configured cell set 205 may be large enough to cover a reasonable mobility area, and mobility within the configured cell set may be accomplished through L1 / L2 signaling.

[0099] In an inter-cell mobility scenario, the cells in the configured cell set 205 may not be collocated, and the UE 115-a may experience different propagation delays to different cells. Therefore, different timing information may be used or required based on the timing advance group (TAG) assignment of the cells. A TAG may refer to a group of cells with which the UE 115 can communicate using the same timing information (e.g., the same timing advance). The configured cell set 205 may include cells in multiple TAGs 225, including a first TAG 225-a, a second TAG 225-b, and a third TAG 225-c.

[0100] UE 115-a can obtain the initial timing advance information of the cell via a RACH procedure. For SpCell, UE 115-a can initiate a RACH procedure to obtain the timing advance information. For SCell, UE 115-a can perform a PDCCH-ordered RACH procedure to obtain the timing advance information. After the initial timing advance information is acquired, one or more cells in the configured cell set 205 may be deactivated. However, in some cases, UE 115-a may not be configured to perform measurements on the deactivated cells 220. Therefore, when the cell is activated, UE 115-a may perform the RACH procedure again to obtain the timing advance information, and by performing the RACH procedure, UE 115-a may experience increased latency and power consumption. This latency and power consumption may eliminate the benefits of dynamic activation of the cell, which may be harmful to the wireless communication system.

[0101] The wireless communication system 100 may support efficient techniques for facilitating uplink synchronization with a cell at a UE 115-a when the cell is activated for communication with the UE 115-a. For example, the described techniques may allow for the maintenance of timing advance information for deactivated cells in the configured cell set 205 so that the timing advance information may be directly signaled to the UE 115-a when the cell is activated. Thus, the UE 115-a may avoid RACH procedures when the cell is activated, resulting in reduced latency and power consumption. In addition, the described techniques may allow for fast L1 or L2 signaling to facilitate seamless UE mobility within the configured cell set 205.

[0102] Figure 3 An example of a wireless communication system 300 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is illustrated. The wireless communication system 300 includes a UE 115-b, which may be a reference Figure 1 and Figure 2The wireless communication system 300 also includes a cell 105-a, a cell 105-b, and a cell 105-c, which may be referenced. Figure 1 and Figure 2 The wireless communication system 300 may implement aspects of the wireless communication system 100. For example, the wireless communication system 300 may support efficient techniques for facilitating uplink synchronization with a cell at a UE 115-b when the cell is activated for communication with the UE 115-b.

[0103] The first cell 105-a can be activated for communication with the UE 115-b and can be a reference cell for timing advance maintenance (e.g., based on UE assistance). The reference cell can be a SpCell or a synchronized SCell. The second cell 105-b and the third cell 105-c can be SCells and can be deactivated for communication with the UE 115-b. The timing advance information of the second cell 105-b and the third cell 105-c (e.g., the deactivated SCell) can be estimated based on downlink reference signal measurements. The first cell 105-a, the second cell 105-b, and the third cell 105-c can send a reference signal 305 that can be received by the UE 115-b. The reference signal 305 can be a synchronization signal block (SSB) or a channel state information (CSI) reference signal (CSI-RS). In some cases, the reference signal 305 may include an existing reference signal for L1 measurement of an L1 or L2 mobility cell set. Because the second cell 105-b and the third cell 105-c may be in the same TAG, the UE 115-b may monitor the reference signal 305 from the second cell 105-b and avoid monitoring the reference signal 305 from the third cell 105-c. For example, only one cell per TAG may be monitored for timing advance information.

[0104] UE 115-b may estimate a first timing advance for communicating with a first cell 105-a, and UE 115-b may estimate a second timing advance for communicating with a second cell 105-b. UE 115-b may determine a timing difference 310 between the first timing advance and the second timing advance. In some examples, UE 115-b may estimate a received reference signal timing difference (e.g., relative to a reference cell) between a reference signal 305 received from the second cell 105-b and a reference signal 305 received from the first cell 105-a, and UE 115-b may determine the timing difference 310 based on the received reference signal timing difference. In some examples, UE 115-b may estimate a downlink propagation delay difference between a first downlink propagation delay for receiving a reference signal 305 from the first cell 105-a and a second propagation delay for receiving a reference signal 305 from the second cell 105-b, and UE 115-b may determine the timing difference 310 based on the downlink propagation delay difference.

[0105] When UE 115-b determines timing difference 310, UE 115-b may report timing difference 310 to network entity 105 (e.g., via first cell 105-a). Timing difference 310 may be based on a downlink timing difference or a downlink propagation delay difference. Network entity 105 may then use the timing difference or the downlink propagation delay difference to determine a timing advance for UE 115-b to use for communicating with second cell 105-b (e.g., when second cell 105-b is activated).

[0106] The UE 115-b may report to the network entity 105 about the timing difference 310, and the report may include a current timing difference (e.g., the timing difference 310) and a timing difference history including past timing differences (e.g., timing differences in the past x ms if the report is not transmitted periodically). In some examples, the UE 115-b may send the timing difference 310 in a dedicated MAC-CE or in joint signaling with the L1 measurement report. If the UE 115-b sends the timing difference 310 in the joint signaling, the measurement object (e.g., the reference signal 305) may be an SBS or a CSI-RS, and the UE 115-b may be configured to indicate the timing difference in the measurement report. For example, the measurement report may include a field for indicating the timing difference 310 (e.g., a downlink propagation delay or a downlink propagation delay difference).

[0107] In some aspects, the UE 115-b may send the timing difference periodically (e.g., with a configured signaling periodicity) or aperiodically. In one example, the UE 115-b may send the timing difference periodically or aperiodically in dedicated or separate signaling (e.g., a dedicated MAC-CE) or in joint signaling with the L1 measurement report. In this example, the network entity 105 may indicate the periodicity with which the UE 115-b may send the timing difference (e.g., periodically with a periodicity f configured by the network). Additionally or alternatively, the network entity 105 may indicate a trigger condition for sending the timing difference aperiodically. The trigger condition may include a timing difference that satisfies a threshold or a change in a reference cell. If the UE 115-b is configured to send the timing difference in joint signaling with the L1 measurement report, one or more of the trigger conditions may be included in the measurement report configuration for the L1 measurement report. In addition, in some cases, a trigger condition (e.g., a trigger event) may be added to a measurement report trigger list. In another example, UE 115 - b may send the timing difference in response to a request from the network entity 105 .

[0108] In an example of a trigger event configuration, a trigger event (e.g., event A7) can be defined for a timing difference between a first cell 105-a (e.g., a reference cell) and a second cell 105-b that meets a threshold. When the first condition (e.g., condition A7-1) is met, UE 115-b can consider that the entry condition of this trigger event is met. The first condition (e.g., inequality A7-1 or entry condition) can be: Abs(Ms-Ref)>threshold, where Ms is the measurement result (e.g., first timing advance) of the second cell 105-b (e.g., serving cell), and Ref is the measurement result (e.g., second timing advance) of the first cell 105-a (e.g., reference cell). When the second condition (e.g., condition A7-2) is met, UE 115-b can consider that the exit condition of this trigger event is met. The second condition (e.g., inequality A7-1 or a leaving condition) may be: Abs(Ms-Ref)>threshold, where Ms is the measurement result (e.g., first timing advance) of the second cell 105-b (e.g., serving cell), and Ref is the measurement result (e.g., second timing advance) of the first cell 105-a (e.g., reference cell). For the measurement of the timing difference, the UE 115-b may also consider the second cell 105-b (e.g., serving cell) indicated by the measurement object associated with the triggering event.

[0109] In some aspects, UE 115-b may receive from network entity 105 an indication of one or more configurations for sending timing differences to network entity 105 (e.g., via first cell 105-a) (e.g., in an RRC configuration message). The configuration for sending the timing difference may indicate a reference cell (e.g., SpCell or other synchronized SCell) for calculating the timing difference. In some cases, network entity 105 may configure multiple reference cells. Additionally or alternatively, the configuration for sending the timing difference may include a timing difference reporting periodicity f, a timing difference aperiodic reporting trigger condition, or an indication of the timing difference report content and related parameters (e.g., a timing difference reporting time window (x ms) for reporting past timing differences in aperiodic reports). If UE 115-b receives an indication of multiple configurations for sending timing differences to network entity 105, UE 115-b may receive an indication of one of multiple configurations to be used to send one or more timing differences (e.g., network entity 105 may use DCI or MAC-CE switching configuration).

[0110] Figure 4 An example of a process flow 400 for supporting UE-assisted uplink synchronization for inter-cell mobility in accordance with one or more aspects of the present disclosure is illustrated. The process flow 400 includes a UE 115-c, which may be a reference Figures 1 to 3 The process flow 400 also includes cells 105-d and 105-e, which may be reference cells. Figures 1 to 3 The process flow 400 may implement aspects of the wireless communication system 100 or the wireless communication system 300. For example, the process flow 400 may support efficient techniques for facilitating uplink synchronization with a cell at a UE 115-c when the cell is activated for communication with the UE 115-c.

[0111] In the following description of process flow 400, the signaling exchanged between UE 115-c, cell 105-d, and cell 105-e may be exchanged in an order different from the example order shown, or the operations performed by UE 115-c, cell 105-d, and cell 105-e may be performed in a different order or at a different time. Some operations may also be omitted from process flow 400, and other operations may be added to process flow 400.

[0112] As described herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0113] At 405, the network entity 105 may send a higher layer control message (e.g., an RRC configuration message) to the UE 115-c via the first cell 105-d, and the UE 115-c may receive the higher layer control message. The higher layer control message may include a configuration of a set of cells with which the UE 115-c may communicate, and the set of cells may include the first cell 105-d and the second cell 105-e. The first cell 105-d may be activated and the second cell 105-e may be deactivated. In some examples, after receiving the higher layer control message (e.g., the RRC configuration message), the UE 115-c may send a confirmation (e.g., an RRC configuration or reconfiguration complete message) to the network entity 105.

[0114] At 410, the UE 115-c may receive a first reference signal from the first cell 105-d, and at 415, the UE 115-c may receive a second reference signal from the second cell 105-e. At 420, the UE 115-c may send an indication of a timing difference (e.g., a timing difference relative to a reference cell) between a first timing advance used for communicating with the first cell 105-d and a second timing advance used for communicating with the second cell 105-e. The UE 115-c may send the indication of the timing difference in a MAC-CE or in a measurement report in uplink control information.

[0115] UE 115-c may determine that the first cell 105-d is a reference cell, and UE 115-c may send an indication of a timing difference between a first timing advance and a second timing advance based on determining that the first cell 105-d is the reference cell. In some examples, UE 115-c may receive an indication that the first cell 105-d is a reference cell from network entity 105 (e.g., via first cell 105-d). Network entity 105 may select the first cell as a reference cell based on a cell quality of the first cell 105-d (e.g., a reference signal received power (RSRP), path loss, or signal to interference plus noise ratio (SINR) associated with communications between the first cell 105-d and UE 115-c) or a cell functionality of the first cell 105-d (e.g., always selecting SpCell as a reference cell).

[0116] In some examples, the UE 115-c may send an indication of the timing difference in a periodic transmission. The UE 115-c may receive an indication of the periodicity of the periodic transmission for sending the indication of the timing difference. In other examples, the UE 115-c may send the indication of the timing difference in a non-periodic transmission (e.g., a single, independent transmission). The UE 115-c may identify one or more trigger conditions for sending the timing difference, and if at least one of the trigger conditions is met, the UE 115-c may send the non-periodic transmission with the timing difference. The trigger condition may include a timing difference that satisfies a timing difference threshold or a change in a reference cell. The UE 115-c may receive an indication of the trigger condition for sending the timing difference. In some examples, the UE 115-c may receive a request to send the timing difference, and the UE 115-c may send the non-periodic transmission with the timing difference in response to receiving the request.

[0117] In some examples, UE 115-c may send multiple timing differences (e.g., for non-periodic reporting of timing advances) between a timing advance used for communicating with a first cell 105-d and a timing advance used for communicating with a second cell 105-e. The multiple timing differences may include a timing difference between a first timing advance used for communicating with the first cell 105-d and a second timing advance used for communicating with the second cell 105-e. The multiple timing differences may also include past timing differences (e.g., a historical record of downlink timing differences relative to a reference cell) between the timing advance used for communicating with the first cell 105-d and the timing advance used for communicating with the second cell 105-e. The past timing differences may include timing differences determined within a threshold amount of time (e.g., x ms), or the past timing differences may include a threshold amount of past timing differences.

[0118] In some examples, UE 115-c may receive an indication of multiple configurations to be used to send a timing difference. UE 115-c may then receive (e.g., in a lower layer control message) an indication of a configuration in the multiple configurations for UE 115-c to use to send a timing difference, and UE 115-c may use the configuration to send the timing difference. The timing difference between the first timing advance and the second timing advance may be based on a downlink propagation delay difference between a first propagation delay associated with the first cell 105-d and a second downlink propagation delay associated with the second cell 105-e. Additionally or alternatively, the timing difference between the first timing advance and the second timing advance may be based on a difference between a first downlink signal reception time associated with the first cell 105-d (e.g., a reception time of a reference signal at 410) and a second downlink signal reception time associated with the second cell 105-e (e.g., a reception time of a reference signal at 415).

[0119] At 425, the UE 115-c may receive a lower layer control message from the first cell 105-d indicating that the second cell 105-e is activated (e.g., for L1 / L2 mobility). The lower layer control message may also indicate a second timing advance for communicating with the second cell 105-e. The network entity 105 may determine the second timing advance based on a timing difference between the first timing advance received from the UE 115-c and the second timing advance. At 430, the UE 115-c may communicate (e.g., exchange control information and data) with the second cell 105-e using the second timing advance.

[0120] Figure 5 A block diagram 500 of a device 505 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 505 may be an example of aspects of the UE 115 as described herein. The device 505 may include a receiver 510, a transmitter 515, and a communication manager 520. The device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0121] The receiver 510 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels related to UE-assisted uplink synchronization for inter-cell mobility, data channels, information channels). The information may be communicated to other components of the device 505. The receiver 510 may utilize a single antenna or a collection of multiple antennas.

[0122] The transmitter 515 may provide means for transmitting signals generated by other components of the device 505. For example, the transmitter 515 may transmit information associated with various information channels (e.g., control channels related to UE-assisted uplink synchronization for inter-cell mobility, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 515 may be co-located with the receiver 510 in a transceiver module. The transmitter 515 may utilize a single antenna or a collection of multiple antennas.

[0123] The communication manager 520, the receiver 510, the transmitter 515, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, the communication manager 520, the receiver 510, the transmitter 515, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0124] In some examples, the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof can be implemented in hardware (e.g., in a communication management circuit). The hardware can include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which is configured to or otherwise supports components for performing the functions described in the present disclosure. In some examples, the processor and a memory coupled to the processor can be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0125] Additionally or alternatively, in some examples, the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting components for performing the functions described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0126] In some examples, communication manager 520 can be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with receiver 510, transmitter 515, or both. For example, communication manager 520 can receive information from receiver 510, transmit information to transmitter 515, or be integrated with receiver 510, transmitter 515, or both to obtain information, output information, or perform various other operations as described herein.

[0127] According to the examples disclosed herein, the communication manager 520 may support wireless communications at the UE. For example, the communication manager 520 may be configured to or otherwise support a component for receiving an indication of a set of cells configured for communicating with the UE. The communication manager 520 may be configured to or otherwise support a component for receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes the reference cell, and the second cell is deactivated. The communication manager 520 may be configured to or otherwise support a component for sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0128] By including or configuring the communication manager 520 according to the examples described herein, the device 505 (e.g., a processor that controls or otherwise couples with the receiver 510, the transmitter 515, the communication manager 520, or a combination thereof) can support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 505 can continue to monitor and perform measurements on reference signals from the deactivated cell and report the timing difference between the timing advance used to communicate with the cell and the timing difference used to communicate with the reference cell, the network entity 105 can maintain the timing advance used by the device 505 to communicate with the cell. Therefore, when the cell is activated, the network entity 105 can signal the timing advance used by the device 505 to communicate with the cell, and the device 505 can avoid performing a RACH procedure to identify the timing advance (e.g., resulting in reduced processing, reduced power consumption, and more efficient utilization of communication resources).

[0129] Figure 6 A block diagram 600 of a device 605 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 605 may be an example of aspects of the device 505 or UE 115 as described herein. The device 605 may include a receiver 610, a transmitter 615, and a communication manager 620. The device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0130] The receiver 610 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels related to UE-assisted uplink synchronization for inter-cell mobility, data channels, information channels). The information may be communicated to other components of the device 605. The receiver 610 may utilize a single antenna or a collection of multiple antennas.

[0131] The transmitter 615 may provide means for transmitting signals generated by other components of the device 605. For example, the transmitter 615 may transmit information associated with various information channels (e.g., control channels related to UE-assisted uplink synchronization for inter-cell mobility, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 615 may be co-located with the receiver 610 in a transceiver module. The transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0132] Device 605 or its various components may be examples of components for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, communication manager 620 may include cell configuration manager 625, reference signal manager 630, timing advance manager 635, or any combination thereof. Communication manager 620 may be an example of various aspects of communication manager 520 as described herein. In some examples, communication manager 620 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using receiver 610, transmitter 615, or both or otherwise cooperate with them. For example, communication manager 620 may receive information from receiver 610, transmit information to transmitter 615, or be integrated with receiver 610, transmitter 615, or both to obtain information, output information, or perform various other operations as described herein.

[0133] According to examples as disclosed herein, the communication manager 620 may support wireless communications at a UE. The cell configuration manager 625 may be configured to or otherwise support components for receiving an indication of a set of cells configured for communicating with the UE. The reference signal manager 630 may be configured to or otherwise support components for receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated. The timing advance manager 635 may be configured to or otherwise support components for sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0134] Figure 7 A block diagram 700 of a communication manager 720 supporting UE-assisted uplink synchronization for inter-cell mobility in accordance with one or more aspects of the present disclosure is shown. The communication manager 720 may be an example of aspects of the communication manager 520, the communication manager 620, or both as described herein. The communication manager 720 or its various components may be examples of components for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, the communication manager 720 may include a cell configuration manager 725, a reference signal manager 730, a timing advance manager 735, a cell mobility manager 740, a reference cell manager 745, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

[0135] According to examples as disclosed herein, the communication manager 720 may support wireless communications at a UE. The cell configuration manager 725 may be configured to or otherwise support components for receiving an indication of a set of cells configured for communicating with the UE. The reference signal manager 730 may be configured to or otherwise support components for receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated. The timing advance manager 735 may be configured to or otherwise support components for sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0136] In some examples, the cell mobility manager 740 may be configured or otherwise support components for receiving an indication that the second cell is activated. In some examples, the timing advance manager 735 may be configured or otherwise support components for receiving an indication of a second timing advance for communicating with the second cell based on the transmit timing difference. In some examples, the timing advance manager 735 may be configured or otherwise support components for communicating with the second cell using the second timing advance.

[0137] In some examples, to support sending an indication of a timing difference, timing advance manager 735 may be configured or otherwise support components for sending periodic transmissions including an indication of a timing difference.

[0138] In some examples, timing advance manager 735 may be configured or otherwise support means for receiving an indication of a periodicity for transmitting periodic transmissions including an indication of a timing difference.

[0139] In some examples, to support sending indications of timing differences, timing advance manager 735 may be configured as or otherwise support means for sending aperiodic transmissions including indications of timing differences.

[0140] In some examples, the timing advance manager 735 may be configured or otherwise support components for identifying one or more trigger conditions for sending a timing difference, wherein sending the aperiodic transmission is based on at least one of the one or more trigger conditions being satisfied.

[0141] In some examples, the one or more trigger conditions include a timing difference satisfying a timing difference threshold, a change in a reference cell, or a combination thereof.

[0142] In some examples, timing advance manager 735 may be configured or otherwise support components for receiving an indication of one or more triggering conditions for sending a timing difference.

[0143] In some examples, timing advance manager 735 may be configured or otherwise support components for receiving a request to send a timing difference, where sending the aperiodic transmission is based on receiving the request.

[0144] In some examples, the timing advance manager 735 can be configured to or otherwise support components for sending a set of multiple timing differences between a timing advance for communicating with a first cell and a timing advance for communicating with a second cell, the set of multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0145] In some examples, reference cell manager 745 may be configured or otherwise support components for receiving an indication that a first cell is a reference cell, where the first cell is selected as the reference cell based on cell quality, cell functionality, or a combination thereof.

[0146] In some examples, the timing advance manager 735 may be configured or otherwise support components for receiving an indication of a set of multiple configurations for the UE to use to send the timing difference. In some examples, the timing advance manager 735 may be configured or otherwise support components for receiving a control message indicating a configuration in a set of multiple configurations for the UE to use to send the timing difference, wherein sending the indication of the timing difference is based on the configuration.

[0147] In some examples, the timing difference between the first timing advance and the second timing advance is based on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0148] In some examples, the indication of the timing difference is sent in a medium access control control element or in a measurement report in uplink control information.

[0149] Figure 8A diagram of a system 800 including a device 805 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 805 may be an example of a device 505, a device 605, or a UE 115 as described herein, or include components of these devices. The device 805 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. The device 805 may include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 820, an input / output (I / O) controller 810, a transceiver 815, an antenna 825, a memory 830, a code 835, and a processor 840. These components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 845).

[0150] I / O controller 810 can manage input signals and output signals of device 805. I / O controller 810 can also manage peripheral devices that are not integrated into device 805. In some cases, I / O controller 810 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 810 can utilize an operating system such as or another known operating system. Additionally or alternatively, I / O controller 810 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 810 may be implemented as part of a processor such as processor 840. In some cases, a user may interact with device 805 via I / O controller 810 or via hardware components controlled by I / O controller 810.

[0151] In some cases, the device 805 may include a single antenna 825. However, in some other cases, the device 805 may have more than one antenna 825, which may be capable of concurrently sending or receiving multiple wireless transmissions. The transceiver 815 may communicate bidirectionally via one or more antennas 825, wired or wireless links, as described herein. For example, the transceiver 815 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 815 may also include a modem for: modulating packets; providing the modulated packets to one or more antennas 825 for transmission; and demodulating packets received from one or more antennas 825. The transceiver 815, or the transceiver 815 and one or more antennas 825 may be examples of transmitters 515, transmitters 615, receivers 510, receivers 610, or any combination thereof or components thereof as described herein.

[0152] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed by the processor 840, cause the device 805 to perform various functions described herein. The code 835 may be stored in a non-transitory computer-readable medium such as a system memory or another type of memory. In some cases, the code 835 may not be directly executable by the processor 840, but may (e.g., when compiled and executed) cause the computer to perform the functions described herein. In some cases, the memory 830 may include a basic I / O system (BIOS), etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0153] The processor 840 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., a memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting UE-assisted uplink synchronization for inter-cell mobility). For example, the device 805 or a component of the device 805 may include a processor 840 and a memory 830 coupled to or coupled to the processor 840, and the processor 840 and the memory 830 are configured to perform the various functions described herein.

[0154] According to the examples disclosed herein, the communication manager 820 may support wireless communications at the UE. For example, the communication manager 820 may be configured to or otherwise support a component for receiving an indication of a set of cells configured for communicating with the UE. The communication manager 820 may be configured to or otherwise support a component for receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes the reference cell, and the second cell is deactivated. The communication manager 820 may be configured to or otherwise support a component for sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0155] By including or configuring the communication manager 820 according to the examples as described herein, the device 805 can support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 805 can continue to monitor the reference signal from the deactivated cell and perform measurements thereon and report the timing difference between the timing advance used to communicate with the cell and the timing difference used to communicate with the reference cell, the network entity 105 can maintain the timing advance used by the device 805 to communicate with the cell. Therefore, when the cell is activated, the network entity 105 can signal the timing advance used by the device 805 to communicate with the cell, and the device 805 can avoid performing a RACH procedure to identify the timing advance (e.g., resulting in reduced processing, reduced power consumption, and more efficient utilization of communication resources).

[0156] In some examples, the communication manager 820 can be configured to perform various operations (e.g., receive, monitor, transmit) using or otherwise cooperating with the transceiver 815, one or more antennas 825, or any combination thereof. Although the communication manager 820 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 820 can be supported or performed by the processor 840, the memory 830, the code 835, or any combination thereof. For example, the code 835 may include instructions that are executable by the processor 840 to cause the device 805 to perform various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein, or the processor 840 and the memory 830 may be otherwise configured to perform or support such operations.

[0157] Fig. 9 A block diagram 900 of a device 905 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 905 may be an example of aspects of the network entity 105 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0158] The receiver 910 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of the device 905. In some examples, the receiver 910 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, the receiver 910 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0159] The transmitter 915 may provide a means for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of the device 905. For example, the transmitter 915 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 915 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 915 may support outputting information by sending signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 915 and the receiver 910 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0160] The communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, the communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0161] In some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof that is configured as or otherwise supports components for performing the functions described in the present disclosure. In some examples, a processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0162] Additionally or alternatively, in some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting components for performing the functions described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0163] In some examples, the communication manager 920 can be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with the receiver 910, the transmitter 915, or both. For example, the communication manager 920 can receive information from the receiver 910, transmit information to the transmitter 915, or be integrated with the receiver 910, the transmitter 915, or both to obtain information, output information, or perform various other operations as described herein.

[0164] According to examples as disclosed herein, the communication manager 920 may support wireless communications at a network entity. For example, the communication manager 920 may be configured to or otherwise support a component for sending an indication of a set of cells configured for communicating with the UE. The communication manager 920 may be configured to or otherwise support a component for sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell. The communication manager 920 may be configured to or otherwise support a component for receiving an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0165] By including or configuring the communication manager 920 according to the examples described herein, the device 905 (e.g., a processor that controls or otherwise couples with the receiver 910, the transmitter 915, the communication manager 920, or a combination thereof) can support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 905 can receive the timing difference between the timing advance at the UE 115 for communicating with the deactivated cell and the timing difference at the UE 115 for communicating with the reference cell, the device 905 can maintain the timing advance used by the UE 115 to communicate with the cell. Therefore, when the cell is activated, the device 905 can signal the timing advance used by the UE 115 to communicate with the cell, and the UE 115 can avoid using the device 905 to perform a RACH procedure to identify the timing advance (e.g., resulting in reduced processing, reduced power consumption, and more efficient utilization of communication resources).

[0166] Fig.10 A block diagram 1000 of a device 1005 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 1005 may be an example of aspects of the device 905 or network entity 105 as described herein. The device 1005 may include a receiver 1010, a transmitter 1015, and a communication manager 1020. The device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0167] The receiver 1010 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of the device 1005. In some examples, the receiver 1010 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, the receiver 1010 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0168] The transmitter 1015 may provide a means for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of the device 1005. For example, the transmitter 1015 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 1015 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 1015 may support outputting information by sending signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1015 and the receiver 1010 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0169] Devices 1005 or their various components may be examples of components for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, communications manager 1020 may include cell configuration manager 1025, reference signal manager 1030, timing advance manager 1035, or any combination thereof. Communications manager 1020 may be an example of various aspects of communications manager 920 as described herein. In some examples, communications manager 1020 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using receiver 1010, transmitter 1015, or both or in other ways in cooperation with them. For example, communications manager 1020 may receive information from receiver 1010, transmit information to transmitter 1015, or be integrated with receiver 1010, transmitter 1015, or both to obtain information, output information, or perform various other operations as described herein.

[0170] According to examples as disclosed herein, the communication manager 1020 may support wireless communications at a network entity. The cell configuration manager 1025 may be configured to or otherwise support components for sending an indication of a set of cells configured for communicating with the UE. The reference signal manager 1030 may be configured to or otherwise support components for sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell. The timing advance manager 1035 may be configured to or otherwise support components for receiving an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0171] Fig.11A block diagram 1100 of a communication manager 1120 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The communication manager 1120 may be an example of aspects of the communication manager 920, the communication manager 1020, or both as described herein. The communication manager 1120 or its various components may be examples of means for performing various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein. For example, the communication manager 1120 may include a cell configuration manager 1125, a reference signal manager 1130, a timing advance manager 1135, a cell mobility manager 1140, a reference cell manager 1145, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses), which communication may include communication within a protocol layer of a protocol stack, communication associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with the network entity 105, between devices, components, or virtualized components associated with the network entity 105), or any combination thereof.

[0172] According to examples as disclosed herein, the communication manager 1120 may support wireless communications at a network entity. The cell configuration manager 1125 may be configured to or otherwise support components for sending an indication of a set of cells configured for communicating with the UE. The reference signal manager 1130 may be configured to or otherwise support components for sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell. The timing advance manager 1135 may be configured to or otherwise support components for receiving an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0173] In some examples, cell mobility manager 1140 may be configured or otherwise support components for sending an indication that the second cell is activated. In some examples, timing advance manager 1135 may be configured or otherwise support components for sending an indication of a second timing advance for communicating with the second cell based on the received timing difference.

[0174] In some examples, to support receiving an indication of a timing difference, timing advance manager 1135 may be configured or otherwise support means for receiving a periodic transmission including an indication of a timing difference.

[0175] In some examples, timing advance manager 1135 may be configured or otherwise support components for sending periodic indications of periodic transmissions from UEs including indications of timing differences.

[0176] In some examples, to support receiving an indication of a timing difference, timing advance manager 1135 may be configured as or otherwise support means for receiving an aperiodic transmission including an indication of a timing difference.

[0177] In some examples, the timing advance manager 1135 can be configured as or otherwise support components for sending an indication of one or more trigger conditions for the UE to send a timing difference, wherein receiving a non-periodic transmission is based on at least one of the one or more trigger conditions being satisfied.

[0178] In some examples, the one or more trigger conditions include a timing difference satisfying a timing difference threshold, a change in a reference cell, or a combination thereof.

[0179] In some examples, the timing advance manager 1135 may be configured or otherwise support components for sending a request for the UE to send a timing difference, where receiving the aperiodic transmission is based on sending the request.

[0180] In some examples, the timing advance manager 1135 can be configured to or otherwise support components for receiving a set of multiple timing differences between a timing advance for communicating with a first cell and a timing advance for communicating with a second cell, the set of multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0181] In some examples, reference cell manager 1145 may be configured or otherwise support components for sending an indication that a first cell is a reference cell, where the first cell is selected as the reference cell based on cell quality, cell functionality, or a combination thereof.

[0182] In some examples, the timing advance manager 1135 may be configured or otherwise support means for sending an indication of a set of multiple configurations for the UE to use to send the timing difference. In some examples, the timing advance manager 1135 may be configured or otherwise support means for sending a control message indicating a configuration in a set of multiple configurations for the UE to use to send the timing difference, wherein receiving the indication of the timing difference is based on the configuration.

[0183] In some examples, the timing difference between the first timing advance and the second timing advance is based on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0184] In some examples, the indication of the timing difference is received in a medium access control control element or in a measurement report in uplink control information.

[0185] Fig.12 A diagram of a system 1200 including a device 1205 supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The device 1205 may be an example of a device 905, a device 1005, or a network entity 105 as described herein, or include components of these devices. The device 1205 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, which communication may include communication through one or more wired interfaces, through one or more wireless interfaces, or any combination thereof. The device 1205 may include components that support output and acquisition of communications, such as a communication manager 1220, a transceiver 1210, an antenna 1215, a memory 1225, a code 1230, and a processor 1235. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1240).

[0186] The transceiver 1210 may support bidirectional communication via a wired link, a wireless link, or both, as described herein. In some examples, the transceiver 1210 may include a wired transceiver and may communicate bidirectionally with another wired transceiver. Additionally or alternatively, in some examples, the transceiver 1210 may include a wireless transceiver and may communicate bidirectionally with another wireless transceiver. In some examples, the device 1205 may include one or more antennas 1215, which may be capable of sending or receiving wireless transmissions (e.g., concurrently). The transceiver 1210 may also include a modem for: modulating a signal; providing the modulated signal for transmission (e.g., via one or more antennas 1215, via a wired transmitter); receiving the modulated signal (e.g., from one or more antennas 1215, from a wired receiver); and demodulating the signal. In some implementations, the transceiver 1210 may include one or more interfaces, such as one or more interfaces coupled to one or more antennas 1215 configured to support various receiving or obtaining operations, or one or more interfaces coupled to one or more antennas 1215 configured to support various transmitting operations or output operations, or a combination thereof. In some implementations, the transceiver 1210 may include or be configured to be coupled to one or more processors or memory components that are operable to perform the following operations: perform or support operations based on received or obtained information or signals; or generate information or other signals for transmission or other output, or any combination thereof. In some implementations, the transceiver 1210, or the transceiver 1210 and one or more antennas 1215, or the transceiver 1210 and one or more antennas 1215 and one or more processors or memory components (e.g., processor 1235, or memory 1225, or both) may be included in a chip or chip component installed in the device 1205. The transceiver 1210 or transceiver 1210 and one or more antennas 1215 or wired interfaces (where applicable) may be examples of transmitter 915, transmitter 1015, receiver 910, receiver 1010, or any combination thereof or components thereof as described herein. In some examples, the transceiver may be operable to support communication via one or more communication links (e.g., communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0187] The memory 1225 may include RAM and ROM. The memory 1225 may store computer-readable, computer-executable code 1230 including instructions that, when executed by the processor 1235, cause the device 1205 to perform various functions described herein. The code 1230 may be stored in a non-transitory computer-readable medium such as a system memory or another type of memory. In some cases, the code 1230 may not be directly executable by the processor 1235, but may (e.g., when compiled and executed) cause the computer to perform the functions described herein. In some cases, the memory 1225 may include a BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0188] The processor 1235 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA, a microcontroller, a programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof). In some cases, the processor 1235 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 1235. The processor 1235 may be configured to execute computer-readable instructions stored in a memory (e.g., a memory 1225) to enable the device 1205 to perform various functions (e.g., functions or tasks supporting UE-assisted uplink synchronization for inter-cell mobility). For example, the device 1205 or a component of the device 1205 may include a processor 1235 and a memory 1225 coupled to the processor 1235, and the processor 1235 and the memory 1225 are configured to perform the various functions described herein. The processor 1235 may be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software such as an operating system, a virtual machine, or a container instance) that can host functions (e.g., by executing code 1230) to perform functions of the device 1205. The processor 1235 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in the device 1205 (such as within the memory 1225). In some specific implementations, the processor 1235 may be a component of a processing system. A processing system may generally refer to a system or a series of machines or components that receive inputs and process these inputs to produce a set of outputs (which may be passed to, for example, other systems or components of the device 1205). For example, the processing system of the device 1205 may refer to a system including various other components or subcomponents of the device 1205, such as the processor 1235, or the transceiver 1210, or the communication manager 1220, or other components or combinations of components of the device 1205. The processing system of device 1205 can be docked with other components of device 1205, and can process information (such as input or signal) received from other components or output information to other components. For example, the chip or modem of device 1205 may include a processing system and an interface for outputting information or for obtaining information or both. The interface may be implemented as or otherwise include a first interface configured to output information and a second interface configured to obtain information. In some specific implementations, the first interface may refer to an interface between the processing system of the chip or modem and a transmitter, so that the device 1205 can send information output from the chip or modem. In some specific implementations, the second interface may refer to an interface between the processing system of the chip or modem and a receiver, so that the device 1205 can obtain information or signal input, and the information can be passed to the processing system.One of ordinary skill in the art will readily recognize that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0189] In some examples, bus 1240 may support communications of a protocol layer (e.g., within a protocol layer) of a protocol stack. In some examples, bus 1240 may support communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within a component of device 1205, or communications performed between different components of device 1205 that may be co-located or located in different locations (e.g., where device 1205 may refer to a system in which one or more of communication manager 1220, transceiver 1210, memory 1225, code 1230, and processor 1235 may be located in one component of different components or divided between different components).

[0190] In some examples, the communication manager 1220 can manage aspects of communications with the core network 130 (e.g., via one or more wired or wireless backhaul links). For example, the communication manager 1220 can manage the delivery of data communications for client devices such as one or more UEs 115. In some examples, the communication manager 1220 can manage communications with other network entities 105 and can include a controller or scheduler for controlling communications with the UE 115 in collaboration with the other network entities 105. In some examples, the communication manager 1220 can support an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between network entities 105.

[0191] According to examples as disclosed herein, the communication manager 1220 may support wireless communications at a network entity. For example, the communication manager 1220 may be configured to or otherwise support a component for sending an indication of a set of cells configured for communicating with the UE. The communication manager 1220 may be configured to or otherwise support a component for sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell. The communication manager 1220 may be configured to or otherwise support a component for receiving an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0192] By including or configuring the communication manager 1220 according to the examples described herein, the device 1205 can support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 1205 can receive the timing difference between the timing advance for communicating with the deactivated cell at the UE 115 and the timing difference for communicating with the reference cell at the UE 115, the device 1205 can maintain the timing advance used by the UE 115 to communicate with the cell. Therefore, when the cell is activated, the device 1205 can signal the timing advance used by the UE 115 to communicate with the cell, and the UE 115 can avoid using the device 1205 to perform a RACH procedure to identify the timing advance (e.g., resulting in reduced processing, reduced power consumption, and more efficient utilization of communication resources).

[0193] In some examples, the communication manager 1220 can be configured to use or otherwise cooperate with the transceiver 1210, one or more antennas 1215 (e.g., where applicable), or any combination thereof to perform various operations (e.g., receive, obtain, monitor, output, transmit). Although the communication manager 1220 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1220 can be supported or performed by the processor 1235, the memory 1225, the code 1230, the transceiver 1210, or any combination thereof. For example, the code 1230 may include instructions that are executable by the processor 1235 to cause the device 1205 to perform various aspects of UE-assisted uplink synchronization for inter-cell mobility as described herein, or the processor 1235 and the memory 1225 may be otherwise configured to perform or support such operations.

[0194] Fig.13 A flowchart illustrating a method 1300 for supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE or a component thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE or a component thereof as described in reference to Figures 1 to 8 The UE 115 described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0195] At 1305, the method may include receiving an indication of a set of cells configured for communicating with the UE. The operations of 1305 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1305 may be performed as described in reference to Figure 7 The cell configuration manager 725 described above is executed.

[0196] At 1310, the method may include receiving a first reference signal from a first cell in a set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes the reference cell, and the second cell is deactivated. The operations of 1310 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1310 may be performed by Figure 7 The reference signal manager 730 described herein performs.

[0197] At 1315, the method may include sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell. The operations of 1315 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1315 may be performed as described in reference to Figure 7 The timing advance manager 735 described above performs

[0198] Fig.14 A flowchart illustrating a method 1400 for supporting UE-assisted uplink synchronization for inter-cell mobility according to one or more aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1400 may be implemented by a network entity or a component thereof as described herein. Figures 1 to 4 as well as Figures 9 to 12 The network entity described herein performs. In some examples, the network entity may execute an instruction set to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform various aspects of the described functions.

[0199] At 1405, the method may include sending an indication of a set of cells configured for communication with the UE. The operations of 1405 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1405 may be performed as described in reference to Fig.11 The cell configuration manager 1125 described above is executed.

[0200] At 1410, the method may include: transmitting a first reference signal via a first cell in a set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell. The operations of 1410 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1410 may be performed by Fig.11 The reference signal manager 1130 described above performs the above.

[0201] At 1415, the method may include receiving an indication of a timing difference between a first timing advance for communicating with a first cell and a second timing advance for communicating with a second cell. The operations of 1415 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1415 may be performed as described in reference to Fig.11 The timing advance manager 1135 described above performs

[0202] The following provides an overview of various aspects of the disclosure:

[0203] Aspect 1: A method for wireless communication at a UE, comprising: receiving an indication of a set of cells configured for communicating with the UE; receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated; and sending an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0204] Aspect 2: The method according to Aspect 1 also includes: receiving an indication that the second cell is activated; receiving an indication of the second timing advance for communicating with the second cell based at least in part on sending the timing difference; and communicating with the second cell using the second timing advance.

[0205] Aspect 3: The method according to any one of aspects 1 to 2, wherein sending the indication of the timing difference comprises: sending a periodic transmission including the indication of the timing difference.

[0206] Aspect 4: The method according to aspect 3 further comprises: receiving an indication of periodicity for sending periodic transmissions including an indication of a timing difference.

[0207] Aspect 5: The method according to any one of aspects 1 to 4, wherein sending the indication of the timing difference comprises: sending an aperiodic transmission including the indication of the timing difference.

[0208] Aspect 6: The method according to Aspect 5 further includes: identifying one or more trigger conditions for sending the timing difference, wherein sending the non-periodic transmission is at least partially based on at least one of the one or more trigger conditions being met.

[0209] Aspect 7: The method according to aspect 6, wherein the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

[0210] Aspect 8: The method according to any one of aspects 6 to 7 further includes: receiving an indication of the one or more triggering conditions for sending the timing difference.

[0211] Aspect 9: The method according to any one of aspects 5 to 8 further comprises: receiving a request to send the timing difference, wherein sending the aperiodic transmission is based at least in part on receiving the request.

[0212] Aspect 10: The method according to any one of Aspects 5 to 9 further includes: sending multiple timing differences between the timing advance used for communicating with the first cell and the timing advance used for communicating with the second cell, the multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0213] Aspect 11: The method according to any one of Aspects 1 to 10 further includes: receiving an indication that the first cell is the reference cell, wherein the first cell is selected as the reference cell at least in part based on cell quality, cell functionality, or a combination thereof.

[0214] Aspect 12: The method according to any one of Aspects 1 to 11 further includes: receiving an indication of multiple configurations for the UE to send the timing difference; and receiving a control message indicating a configuration among the multiple configurations for the UE to send the timing difference, wherein sending the indication of the timing difference is at least partially based on the configuration.

[0215] Aspect 13: A method according to any one of Aspects 1 to 12, wherein the timing difference between the first timing advance and the second timing advance is at least partially based on the downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, the difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0216] Aspect 14: The method according to any one of aspects 1 to 13, wherein the indication of the timing difference is sent in a medium access control control element or in a measurement report in uplink control information.

[0217] Aspect 15: A method for wireless communication at a network entity, comprising: sending an indication of a set of cells configured for communicating with a UE; sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; and receiving an indication of a timing difference between a first timing advance for communicating with the first cell and a second timing advance for communicating with the second cell.

[0218] Aspect 16: The method according to aspect 15 further includes: sending an indication that the second cell is activated; and sending an indication of the second timing advance for communicating with the second cell based at least in part on receiving the timing difference.

[0219] Aspect 17: The method according to any one of aspects 15 to 16, wherein receiving the indication of the timing difference comprises: receiving a periodic transmission including the indication of the timing difference.

[0220] Aspect 18: The method according to aspect 17 further comprises: sending an indication of the periodicity of the periodic transmission from the UE including the indication of the timing difference.

[0221] Aspect 19: The method according to any one of aspects 15 to 18, wherein receiving the indication of the timing difference comprises: receiving an aperiodic transmission including the indication of the timing difference.

[0222] Aspect 20: The method according to Aspect 19 also includes: sending an indication of one or more trigger conditions for the UE to send the timing difference, wherein receiving the non-periodic transmission is at least partially based on at least one of the one or more trigger conditions being met.

[0223] Aspect 21: The method according to aspect 20, wherein the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

[0224] Aspect 22: The method according to any one of aspects 19 to 21 further comprises: sending a request for the UE to send the timing difference, wherein receiving the non-periodic transmission is at least partially based on sending the request.

[0225] Aspect 23: The method according to any one of Aspects 19 to 22 further includes: receiving multiple timing differences between a timing advance used for communicating with the first cell and a timing advance used for communicating with the second cell, the multiple timing differences including the timing difference between the first timing advance and the second timing advance.

[0226] Aspect 24: The method according to any one of Aspects 15 to 23 further includes: sending an indication that the first cell is the reference cell, wherein the first cell is selected as the reference cell at least in part based on cell quality, cell functionality, or a combination thereof.

[0227] Aspect 25: The method according to any one of Aspects 15 to 24 further includes: sending an indication of multiple configurations for the UE to send the timing difference; and sending a control message indicating a configuration among the multiple configurations for the UE to send the timing difference, wherein receiving the indication of the timing difference is at least partially based on the configuration.

[0228] Aspect 26: A method according to any one of Aspects 15 to 25, wherein the timing difference between the first timing advance and the second timing advance is at least partially based on the downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, the difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

[0229] Aspect 27: The method according to any one of aspects 15 to 26, wherein the indication of the timing difference is received in a medium access control control element or in a measurement report in uplink control information.

[0230] Aspect 28: An apparatus for performing wireless communications at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 1 to 14.

[0231] Aspect 29: An apparatus for wireless communication at a UE, comprising: at least one component for performing a method according to any one of aspects 1 to 14.

[0232] Aspect 30: A non-transitory computer-readable medium storing a code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method according to any one of aspects 1 to 14.

[0233] Aspect 31: An apparatus for wireless communication at a network entity, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 15 to 27.

[0234] Aspect 32: An apparatus for wireless communication at a network entity, comprising: at least one component for performing a method according to any one of aspects 15 to 27.

[0235] Aspect 33: A non-transitory computer-readable medium storing code for wireless communication at a network entity, the code comprising instructions executable by a processor to perform the method according to any one of aspects 15 to 27.

[0236] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0237] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0238] The information and signals described herein may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the specification may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0239] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0240] The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. If implemented using software executed by a processor, the functions may be stored as one or more instructions or codes of a computer-readable medium, or sent using one or more instructions or codes of a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these items. Features that implement the functions may also be physically located at different locations, including being distributed so that the various parts of the functions are implemented at different physical locations.

[0241] Computer-readable medium includes both non-transient computer storage medium and communication medium, and the communication medium includes any medium that promotes computer program to be transferred from one position to another position.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.By way of example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage device, disk storage device or other magnetic storage device, or can be used for carrying or storing desired program code parts and can be accessed by general or special-purpose computer or general or special-purpose processor in the form of instruction or data structure Any other non-transient medium.Moreover, any connection is appropriately referred to as computer-readable medium.For example, if software is sent from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are included in the definition of computer-readable medium. As used herein, disks and optical disks include CDs, laser disks, optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks. Disks can reproduce data magnetically, and optical disks can reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0242] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or Bc or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0243] The term "determining" encompasses a variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database or other data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data stored in a memory), etc. Additionally, "determining" may include parsing, obtaining, selecting, choosing, establishing, and other such similar actions.

[0244] In the drawings, similar components or features may have the same reference label. In addition, various components of the same type may be distinguished by following the reference label with a dash and a second label to distinguish between the similar components. If only the first reference label is used in the specification, the description may apply to any of the similar components having the same first reference label, regardless of the second reference label or other subsequent reference labels.

[0245] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0246] The description herein is provided to enable one of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receiving an indication of a set of cells configured for communication with the UE; receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the second cell is deactivated; and sending an indication of a timing difference between a first timing advance used for communicating with the first cell and a second timing advance used for communicating with the second cell.

2. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: receiving an indication that the second cell is activated; receiving an indication of the second timing advance for communicating with the second cell based at least in part on sending the timing difference; and The second timing advance is used to communicate with the second cell.

3. The apparatus of claim 1 , wherein the instructions for sending the indication of the timing difference are executable by the processor to cause the apparatus to: The sending comprises periodic sending of said indication of said timing difference.

4. The apparatus of claim 3, wherein the instructions are further executable by the processor to cause the apparatus to: An indication of a periodicity for sending a periodic transmission including an indication of a timing difference is received.

5. The apparatus of claim 1 , wherein the instructions for sending the indication of the timing difference are executable by the processor to cause the apparatus to: The sending comprises aperiodic sending of said indication of said timing difference.

6. The apparatus of claim 5, wherein the instructions are further executable by the processor to cause the apparatus to: One or more trigger conditions for transmitting the timing difference are identified, wherein transmitting the aperiodic transmission is based at least in part on at least one of the one or more trigger conditions being satisfied. 7 . The apparatus of claim 6 , wherein the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

8. The apparatus of claim 6, wherein the instructions are further executable by the processor to cause the apparatus to: An indication of the one or more triggering conditions for sending the timing difference is received.

9. The apparatus of claim 5, wherein the instructions are further executable by the processor to cause the apparatus to: A request is received to transmit the timing difference, wherein transmitting the aperiodic transmission is based at least in part on receiving the request.

10. The apparatus of claim 5, wherein the instructions are further executable by the processor to cause the apparatus to: A plurality of timing differences between a timing advance used for communicating with the first cell and a timing advance used for communicating with the second cell are transmitted, the plurality of timing differences including the timing difference between the first timing advance and the second timing advance.

11. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: An indication is received that the first cell is the reference cell, wherein the first cell is selected as the reference cell based at least in part on cell quality, cell functionality, or a combination thereof.

12. The apparatus of claim 1, wherein the instructions are further executable by the processor to cause the apparatus to: Receiving an indication of a plurality of configurations for the UE to use to send the timing difference; and receiving a control message indicating a configuration among the plurality of configurations for the UE to use to send the timing difference, wherein sending the indication of the timing difference is based at least in part on the configuration.

13. An apparatus according to claim 1, wherein the timing difference between the first timing advance and the second timing advance is based at least in part on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

14. The apparatus of claim 1, wherein the indication of the timing difference is sent in a medium access control control element or in a measurement report in uplink control information.

15. An apparatus for wireless communication at a network entity, comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: sending an indication of a set of cells configured for communication with a user equipment (UE); sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; as well as An indication of a timing difference between a first timing advance used for communicating with the first cell and a second timing advance used for communicating with the second cell is received.

16. The apparatus of claim 15, wherein the instructions are further executable by the processor to cause the apparatus to: sending an indication that the second cell is activated; and An indication of the second timing advance for communicating with the second cell is sent based at least in part on receiving the timing difference.

17. The apparatus of claim 15, wherein the instructions for receiving the indication of the timing difference are executable by the processor to cause the apparatus to: Receiving comprises periodic transmission of said indication of said timing difference.

18. The apparatus of claim 17, wherein the instructions are further executable by the processor to cause the apparatus to: An indication of periodicity of periodic transmissions from the UE including an indication of a timing difference is sent.

19. The apparatus of claim 15, wherein the instructions for receiving the indication of the timing difference are executable by the processor to cause the apparatus to: Receiving includes an aperiodic transmission of said indication of said timing difference.

20. The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: An indication of one or more triggering conditions for the UE to transmit the timing difference is transmitted, wherein receiving the aperiodic transmission is based at least in part on at least one of the one or more triggering conditions being satisfied.

21. The apparatus of claim 20, wherein the one or more trigger conditions include the timing difference satisfying a timing difference threshold, a change in the reference cell, or a combination thereof.

22. The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: A request is sent to cause the UE to send the timing difference, wherein receiving the aperiodic transmission is based at least in part on sending the request.

23. The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: A plurality of timing differences between a timing advance used for communicating with the first cell and a timing advance used for communicating with the second cell are received, the plurality of timing differences including the timing difference between the first timing advance and the second timing advance.

24. The apparatus of claim 15, wherein the instructions are further executable by the processor to cause the apparatus to: An indication is sent that the first cell is the reference cell, wherein the first cell is selected as the reference cell based at least in part on cell quality, cell functionality, or a combination thereof.

25. The apparatus of claim 15, wherein the instructions are further executable by the processor to cause the apparatus to: sending an indication of a plurality of configurations for the UE to use to send the timing difference; and sending a control message indicating a configuration among the plurality of configurations for the UE to use to send the timing difference, wherein receiving the indication of the timing difference is based at least in part on the configuration.

26. An apparatus according to claim 15, wherein the timing difference between the first timing advance and the second timing advance is based at least in part on a downlink propagation delay difference between a first downlink propagation delay associated with the first cell and a second downlink propagation delay associated with the second cell, a difference between a first downlink signal reception time associated with the first cell and a second downlink signal reception time associated with the second cell, or a combination thereof.

27. The apparatus of claim 15, wherein the indication of the timing difference is received in a medium access control control element or in a measurement report in uplink control information.

28. A method for wireless communication at a user equipment (UE), comprising: receiving an indication of a set of cells configured for communication with the UE; receiving a first reference signal from a first cell in the set of cells and a second reference signal from a second cell in the set of cells, wherein the first cell is activated and includes a reference cell and the second cell is deactivated; as well as An indication of a timing difference between a first timing advance used for communicating with the first cell and a second timing advance used for communicating with the second cell is sent.

29. The method according to claim 28, further comprising: receiving an indication that the second cell is activated; receiving an indication of the second timing advance for communicating with the second cell based at least in part on sending the timing difference; and The second timing advance is used to communicate with the second cell.

30. A method for wireless communication at a network entity, comprising: sending an indication of a set of cells configured for communication with a user equipment (UE); sending a first reference signal via a first cell in the set of cells, wherein the first cell is activated and includes a reference cell, and the first cell is different from a second deactivated cell; as well as An indication of a timing difference between a first timing advance used for communicating with the first cell and a second timing advance used for communicating with the second cell is received.

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