Techniques for handover in non-terrestrial networks

Abstract

Methods, systems, and devices for wireless communication are described. These particularly relate to techniques for handover in non-terrestrial networks. A user equipment (UE) may communicate with a first cell. The UE may receive a request to report one or more parameters associated with handover from the first cell to a second cell during a time period. The one or more parameters may include an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay rate of change during the time period, or both. The UE may send a message indicating the parameter in response to the request. The UE may receive an indication of an uplink grant occasion based on indicating the parameter, the uplink grant occasion associated with the handover during the time period.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. patent application No. 17 / 844,574, entitled “TECHNIQUES FOR HANDOVER IN NON-TERRESTRIAL NETWORKS,” filed by Shrestha et al. on June 20, 2022, which is assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0003] The following relates to wireless communications, including techniques for handover in non-terrestrial networks. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, 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 use 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). A wireless multiple access communication system may include one or more base stations, each of which supports wireless communication for communication devices, which may be referred to as user equipment (UE). Some wireless communication systems may support non-terrestrial networks. For example, a satellite may communicate with a UE and forward some communications to another network entity (such as a base station). However, such networks may experience relatively high signaling overhead and congestion. Summary of the invention

[0005] The described technology relates to improved methods, systems, devices and apparatuses for supporting technologies for handover in non-terrestrial networks. The described technology may enable a device to perform a handover from a source cell to a target cell (e.g., without a random access channel (RACH) procedure). For example, a user equipment (UE) and a network entity (e.g., one or more base stations, satellites, or both) may communicate in a system. The UE may communicate with a serving cell (e.g., a source cell), which is associated with a network entity. The device may perform a handover operation from the serving cell to the target cell according to the technology described herein. For example, the UE and the network entity may exchange signaling to implement a conditional cell handover (e.g., a RACH-free cell handover). In some examples, the network entity may request the UE to report one or more parameters associated with the conditional cell handover. The parameter may indicate a parameter such as an estimated propagation delay, an estimated rate of change of the following propagation, or both. The UE may send a report message indicating the parameter and receive an indication of an uplink grant. The UE may use the uplink grant to send a message to the target cell indicating that the handover is complete (e.g., because the source cell forwards information for communicating with the UE to the target cell, no RACH procedure with the target cell is performed). Additionally or alternatively, the UE may initiate a RACH with the target cell based on satisfying one or more thresholds.

[0006] A method for wireless communication at a user equipment (UE) is described. The method may include: receiving a request from a first cell to report one or more parameters, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; sending a message indicating the one or more parameters to the first cell in response to receiving the request; and receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0007] 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 a request from a first cell to report one or more parameters, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of the estimated propagation delay between the UE and the second cell during the time period, or both; send a message indicating the one or more parameters to the first cell in response to receiving the request; and receive an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0008] Another apparatus for wireless communication at a UE is described. The apparatus may include: a means for receiving a request from a first cell to report one or more parameters, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of the estimated propagation delay between the UE and the second cell during the time period, or both; a means for sending a message indicating the one or more parameters to the first cell in response to receiving the request; and a means for receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0009] 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 perform the following items: receiving a request for reporting one or more parameters from a first cell, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both; sending a message indicating the one or more parameters to the first cell in response to receiving the request; and receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0010] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following: sending the message or a second message indicating an estimated propagation delay for a second time period that occurs before the time period.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: sending the message indicating the one or more parameters, wherein the one or more parameters indicate the location of the UE, the change in positioning of the UE, the speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0012] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following: receiving a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters may be based on receiving the second message.

[0013] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: receiving a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: receiving a second request to perform measurements of the synchronization signal blocks of the second cell.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following: receiving a second message indicating one or more measurement parameters, wherein the one or more measurement parameters indicate a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof; and performing the measurement of the synchronization signal block based on the one or more measurement parameters.

[0016] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: determining a handover time associated with the handover of the cell based on the first cell being one of an earth-fixed cell or an earth-mobile cell.

[0017] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing the following: receiving a second message indicating that the timing of the second cell for the time period is advanced.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing: determining that a difference between a calculated timing advance and the timing advance indicated by the second message satisfies a threshold; and sending a first message of a random access channel procedure to the second cell based on the satisfied threshold.

[0019] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing the following: sending a first message of a random access channel procedure to the second cell based on the lapse of the time period.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: determining whether an initial timing error for a timing advance may be within half of a cyclic prefix (CP) of a target cell; and releasing the uplink grant opportunity or handover resource based on determining that the initial timing error may not be within half of the CP of the target cell.

[0021] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing the following: sending one or more messages according to a feedback type associated with the uplink grant opportunity.

[0022] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following: determining that one or more parameters satisfy one or more thresholds, the one or more parameters including a timing advance, a location of the UE, a number of uplink grant opportunities including the uplink grant opportunity, a valid time window associated with the uplink grant opportunity, or any combination thereof; and sending a first message of a random access channel procedure based on the one or more thresholds satisfied.

[0023] A method for wireless communication at a network entity associated with a first cell is described. The method may include: sending a request to report one or more parameters, the one or more parameters associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; receiving a message indicating the one or more parameters in response to the sent request; and sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0024] An apparatus for wireless communication at a network entity associated with a first cell 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 a request for reporting one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; receive a message indicating the one or more parameters in response to the sent request; and send an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0025] Another apparatus for wireless communication at a network entity associated with a first cell is described. The apparatus may include: means for sending a request to report one or more parameters, the one or more parameters associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated rate of change of the propagation delay between the UE and the second cell during the time period, or both; means for receiving a message indicating the one or more parameters in response to the sent request; and means for sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0026] A non-transitory computer-readable medium storing code for wireless communication at a network entity associated with a first cell is described. The code may include instructions executable by a processor to perform the following: sending a request for reporting one or more parameters, the one or more parameters associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both; receiving a message indicating the one or more parameters in response to the sent request; and sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0027] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing the following: receiving the message or a second message indicating an estimated propagation delay for a second time period that occurs before the time period.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: receiving the message indicating the one or more parameters, wherein the one or more parameters indicate the location of the UE, the change in positioning of the UE, the speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0029] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following: sending a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters may be based on receiving the second message.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: sending a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

[0031] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: sending a second request to perform measurements of the synchronization signal blocks of the second cell.

[0032] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: sending a second message indicating one or more measurement parameters, wherein the one or more measurement parameters indicate a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: determining a handover time associated with the handover of the cell based on the first cell being one of an earth-fixed cell or an earth-mobile cell.

[0034] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing the following: sending a second message indicating a timing advance of the second cell for the time period.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: receiving a first message of a random access channel procedure based on a difference between a timing advance of the UE and the timing advance indicated by the second message satisfying a threshold.

[0036] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing: receiving a first message of a random access channel procedure based on the time period lapsed.

[0037] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: based on the initial timing error for the timing advance not being within half of the cyclic prefix (CP) of the target cell, an uplink message cannot be received via the uplink grant opportunity or handover resource.

[0038] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, means, or instructions for performing: receiving one or more messages according to a feedback type associated with the uplink grant opportunity.

[0039] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the following items: receiving a first message of a random access channel procedure based on one or more parameters satisfying one or more thresholds, the one or more parameters including a timing advance, a location of the UE, a number of uplink grant opportunities including the uplink grant opportunity, a valid time window associated with the uplink grant opportunity, or any combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 An example of a wireless communication system supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated.

[0041] Figure 2 An example of a wireless communication system supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated.

[0042] Figure 3 An example of a timeline for supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated.

[0043] Figure 4 An example of a process flow supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated.

[0044] Figure 5 and Figure 6 A block diagram of a device supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0045] Figure 7 A block diagram of a communications manager supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0046] Figure 8 A diagram of a system including devices supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0047] Fig. 9 and Fig.10 A block diagram of a device supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0048] Fig.11 A block diagram of a communications manager supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0049] Fig.12 A diagram of a system including devices supporting techniques for handover in a non-terrestrial network is shown in accordance with one or more aspects of the present disclosure.

[0050] Figures 13 to 16 A flow chart illustrating a method of supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0051] Some wireless communication systems may support non-terrestrial networks (NTNs). For example, a satellite may communicate with a user equipment (UE) and a network entity or forward communications between the user equipment and the network entity. A cell handover (CHO) of a UE from a source cell to a target cell may be based on time or location. A UE may communicate with a first cell (e.g., a source cell) and perform a random access channel (RACH) procedure to handover to a second cell (e.g., a target cell). However, such techniques may be relatively inefficient. For example, in the case of a gateway or a satellite switch, a large number of UEs may be handed over from a source cell to a target cell. In such examples, a large number of UEs may initiate a random access procedure with a target cell at the same time or nearly at the same time (e.g., a message of a RACH procedure is sent via the same or similar resources), which may cause congestion and relatively high signaling overhead in the system.

[0052] The technology described herein may provide a RACH-free handover in a wireless communication system (e.g., NTN), which may improve system efficiency. For example, a wireless device may communicate signaling to implement a RACH-free handover from a source cell to a target cell. As an illustrative example, a network entity may request a UE to report information for a conditional handover (e.g., a RACH-free handover). The UE may indicate the information (e.g., auxiliary information) in a report message. The information may include differential delay (e.g., estimated propagation delay), a rate of change of change in the service link delay, differential delay in a future time window (e.g., an expected differential delay during a handover period), UE positioning, satellite positioning, etc., which may enable cell handover for NTN. In some examples, the source cell may forward the auxiliary information to the target cell. By communicating such information, accurate parameters (e.g., timing advance (TA), offset, etc.) may be used for handover and subsequent communications between the UE and the target cell. Thus, the network may provide an uplink grant to the UE to send a handover completion message without performing a RACH procedure. Additionally or alternatively, if one or more thresholds for no RACH procedure are not met, the UE may initiate a RACH procedure with the target cell. In some examples, the UE may determine a feedback type for a pre-allocated uplink grant. In such examples, the UE may send one or more retransmissions of an uplink grant message, ignore the uplink grant, or both based on the feedback type.

[0053] Aspects of the disclosure are first described in the context of a wireless communication system. Aspects of the disclosure are then described in the context of a timeline and process flow. Aspects of the disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow diagrams related to techniques for handover in a non-terrestrial network.

[0054] Figure 1An example of a wireless communication system 100 supporting techniques for handover in a non-terrestrial network 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).

[0055] 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, etc. 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).

[0056] 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 both 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.

[0057] 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 yet 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 a second node.

[0058] 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 each network entity 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 .

[0059] 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 Gigabit 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, standalone) 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).

[0060] 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)).

[0061] The functional split between CU 160, DU 165, and RU 170 is flexible and may 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 may be employed between CU 160 and DU 165 such that CU 160 may support one or more layers of a protocol stack and DU 165 may support one or more different layers of a protocol stack. In some examples, CU 160 may 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 may be within the protocol layer (e.g., some functions of the protocol layer may be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer are performed by a different one of CU 160, DU 165, or RU 170). CU 160 may be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. CU 160 may be connected to one or more DUs 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and DU 165 may 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 an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 105 that communicate via such communication links.

[0062] 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., a 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 terminal (IAB-MT) controlled (e.g., scheduled) by a DU 165 of a coupled IAB donor. The IAB-MT may include an independent antenna group 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 a communication link with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration of the access network (e.g., downstream). 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.

[0063] Where the techniques described herein are applied to the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture may be configured to support the techniques for handover in a non-terrestrial network 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).

[0064] 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 terminology, 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 items such as appliances or vehicles, meters, etc.

[0065] 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.

[0066] The UE 115 and the network entity 105 may use resources associated with one or more carriers to wirelessly communicate with each other via one or more communication links 125 (e.g., access links). The term "carrier" may refer to a group 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 with 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 these devices and any part (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 part 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).

[0067] The signal waveform transmitted via the carrier wave may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM technology, a resource element may refer to a symbol period (e.g., the duration of a modulation symbol) and a resource of a subcarrier, where 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 (e.g., in the transmission duration) a relatively high number of resource elements 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.

[0068] 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 radio frame 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).

[0069] 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, the 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 a plurality of 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 ) sampling period. The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0070] 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., a certain 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)).

[0071] Physical channels may be multiplexed using carriers for communication according to various techniques. For example, physical control channels and physical data channels may be multiplexed via downlink carriers using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique for signaling. 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 group of UEs 115. For example, one or more of the UEs 115 may monitor or search the control region for 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 the control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with the 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 .

[0072] 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 provide coverage for various coverage areas 110 using the same or different radio access technologies.

[0073] The wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable, low-latency or critical functions. Ultra-reliable communication may include private communication or group communication, and may be supported by one or more services (such as push-to-talk, video or data). Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency and ultra-reliable low-latency may be used interchangeably herein.

[0074] In some examples, the UE 115 may be configured to support communication directly with other UEs 115 over 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.

[0075] 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 (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. 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 via a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to an IP service 150 for 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.

[0076] The wireless communication system 100 may operate using one or more frequency bands that may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally speaking, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is about one decimeter to one meter. 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 structures so that macro cells provide services to UEs 115 located indoors. Communications using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to communications using lower frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0077] The wireless communication system 100 may utilize both licensed RF spectrum bands and unlicensed RF spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology using unlicensed bands such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating using unlicensed RF spectrum bands, devices such as network entities 105 and UE 115 may employ carrier sensing for conflict detection and avoidance. In some examples, operations using unlicensed bands may be based on a carrier aggregation configuration combined with component carriers operating using licensed bands (e.g., LAA). Operations using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, and the like.

[0078] The network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can 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 that can support MIMO operations 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 set of multiple rows and columns of antenna ports that the network entity 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may include one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals sent via the antenna ports.

[0079] The network entity 105 or UE 115 may 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 sent, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, the 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.

[0080] 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 along a particular orientation 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 orientation (e.g., relative to the antenna array of the transmitting device or the receiving device or relative to some other orientation).

[0081] UE 115 and network entity 105 may support retransmission of data to increase the likelihood of data being successfully received. Hybrid automatic repeat request (HARQ) feedback is a technique for increasing the likelihood of correctly receiving data via a communication link (e.g., communication link 125, D2D communication link 135). HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device may support same-slot HARQ feedback, in which case the device may provide HARQ feedback in a specific time slot for data received via a previous symbol in the time slot. In some other examples, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0082] The wireless communication system 100 may support non-terrestrial network communications. For example, one or more network entities 105 may be examples of satellites or another NTN device. In some examples, the wireless communication system 100 may support RACH-free handover between cells in the system. For example, the UE 115 may communicate with a source cell (e.g., a network entity 105, a component of the network entity 105), which may be additionally or alternatively referred to as a serving cell. The UE 115 may undergo a handover procedure to switch from the source cell to the target cell (e.g., another network entity 105, a component of the network entity 105). The UE 115 may communicate information (such as auxiliary information) with the network to achieve cell handover without RACH. For example, the UE 115 may exchange signaling indicating one or more parameters (e.g., timing advance, location information, etc.), and the UE 115 may use such parameters to communicate with the target cell. In such examples, UE 115 may be provided with an uplink grant for communicating a handover complete message to a target cell using these parameters (eg, in the absence of a RACH procedure with the target cell), which may achieve improved system efficiency, among other things.

[0083] Figure 2 An example of a wireless communication system 200 that supports techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated. The wireless communication system 200 may support a non-terrestrial network (NTN). The network entities 105-a, 105-b, and 105-c may be network entities (e.g., base stations, satellites, or other entities). For example, the network entity 105-a may communicate with the UE 115-a and the network entity 105-c, or forward communications between the UE 115-a and the network entity 105-c, which may be referenced herein. Figure 1 Examples of the corresponding devices described.

[0084] Generally speaking, the wireless communication system 200 shows an example of a network entity 105-a (e.g., a satellite of NTN) serving a UE 115-a via a source cell 220-a and a network entity 105-b having a target cell 220-b for the UE 115-a to communicate after a handover, but it should be understood that any number or type of devices or cells may be implemented in the wireless communication system 200. For example, a single satellite may include the source cell 220-a and the target cell 220-b, a network entity 105-c may be used in addition to or in lieu of the network entity 105-a or 105-b, etc.

[0085] The source cell 220-a can be referred to as the serving cell 220-a of the UE 115-a. For example, the source cell 220-a can be the serving cell 220-a with which the UE 115-a has established a communication link (e.g., via a previous RACH procedure or a RACH-less handover). In some examples, although described with reference to cell handover, the techniques described herein can additionally or alternatively be applied to any handover event (e.g., hard handover, inter-frequency handover, intra-cell handover, inter-cell handover, intra-frequency handover, soft handover, etc.).

[0086] In some examples, the wireless communication system 200 can support time- and location-based handovers (e.g., for NTN). For example, a device can perform one or more cell handover events based on whether one or more thresholds (e.g., conditions) are met. As an illustrative example, a location-based handover (e.g., CondEvent D1) or a time-based handover (e.g., CondEvent T1) can be performed based on one or more thresholds. A location-based handover (e.g., CondEvent D1) can have an entry condition that is met when a first condition (e.g., condition D1-1) and a second condition (e.g., condition D1-2) are met (e.g., when greater than a threshold). For example, if the first condition and the second condition are met, the device can perform a location-based handover. For example, when the difference between the UE reference location (MI1) and the hysteresis parameter of the event (Hys) meets the threshold "Thresh1" (e.g., MI1 - Hys > Thresh1), the first condition can be met. When the difference between the reference UE location (MI2) and the hysteresis parameter of the event (Hys) meets the threshold "Thresh2" (e.g., MI1 - Hys <, >, or = Thresh2), the second condition can be met. In some examples, a device can "leave" a cell handover event (e.g., stop communicating associated with the cell handover event) based on meeting one or more thresholds (e.g., a leave condition). For example, such a leave condition can be met when a third condition (e.g., condition D1-3) and a fourth condition (e.g., condition D1-4) are greater than a threshold (e.g., Ml1 + Hys < Thresh1 and Ml2 - Hys > Thresh2). In some examples, a threshold distance (e.g., a maximum distance for performing a cell handover) can be defined (e.g., as 3000 km, 16 bits, or a value of both).

[0087] In some examples, the device may perform one or more cell handover events as part of a time-based handover (e.g., CondEvent T1) based on one or more thresholds. For example, the time-based handover may have an entry condition that is satisfied when a first condition (e.g., condition T1-1) is satisfied (e.g., when greater than a threshold). When a condition (e.g., condition T1-2) is satisfied (e.g., when greater than a threshold), an exit condition may be satisfied. For example, when an entry condition (e.g., Mt>Thresh1, where Mt is a reference time associated with the UE) is satisfied and an exit condition (e.g., Mt>Thresh1+duration) is satisfied, the device may perform a time-based handover. In some examples, a threshold time measurement (e.g., a T2 timer indicating a maximum time) may be defined as an integer (e.g., INTEGER(1.6000)) including a step value, where each step is a time duration (e.g., 100 ms). In some examples, a time measurement may have a defined maximum value (e.g., 600 seconds).

[0088] In some examples, the wireless communication system 200 may support cell handover via a RACH procedure. For example, UE 115-a may communicate with a source cell 220-a and perform a RACH procedure to handover UE 115-a to a target cell 220-b for subsequent communication. In some examples, the RACH procedure may be an example of a two-step RACH procedure. In a two-step RACH procedure, UE 115-a may send a first message (e.g., msgA) and receive a second message (e.g., msgB) from a target cell 220-b. Based on the first message and the second message of the exchange RACH procedure, UE 115-a may establish communication with the target cell 220-b and communicate according to the message reception and reception (e.g., UE 115-a may use timing advance, resources, identifiers (IDs), or other examples of parameters for communicating with the target cell 220-b, which are obtained as part of the RACH procedure). Additionally or alternatively, the RACH procedure may be an example of a four-step RACH procedure (eg, the UE may send msg1 and msg3 and receive msg2 and msg4 to establish communication).

[0089] In some other examples, the wireless communication system 200 may support cell handover without RACH (e.g., RACH-free handover). For example, the serving cell 220-a and the target cell 220-b may be synchronized, and the network entity 105-a may transmit an uplink grant for the UE 115-a to transmit a message indicating that the handover is complete (e.g., a handover complete message, e.g., without sending a RACH message). In some such examples, the serving cell 220-a may forward information to the target cell 220-b to achieve such handover (e.g., the serving cell 220-a may obtain parameters as described herein and forward such auxiliary information to the target cell 220-b, which may use the obtained parameters to communicate with the UE 115-a without obtaining the parameters from the RACH procedure).

[0090] If UE 115-a receives an uplink grant and successfully completes the handover, UE 115-a may avoid one or more of the steps in the RACH procedure (e.g., UE 115-a may not communicate a physical RACH (PRACH) Msg1 and a random access response (RAR) message (Msg3)). In some examples, the network (e.g., network entity 105) may configure parameters for UE 115-a (such as a timing advance indicator (e.g., N) indicating an index of a timing advance value for UE 115-a. ta =0)) for communicating with the target cell 220-b. In some examples, the source cell 220-a may configure the UE 115-a to use a pre-allocated uplink grant. In some examples, no pre-allocated uplink grant is provided, and the UE monitors a channel (e.g., a physical downlink control channel (PDCCH)) of the target cell 220-b to receive an uplink grant.

[0091] In some examples, a RACH-free handover or a handover without some RACH steps can improve communication efficiency and reduce signaling overhead. For example, in the case of a gateway or satellite switch (e.g., the serving satellite may be moving such that one or more UEs are leaving the coverage area of ​​the serving satellite and / or entering the coverage area of ​​the satellite of the target cell 220-b), a large number of UEs 115-a may be handed over from the source cell 220-a to the target cell 220-b. In such examples, a RACH-free conditional handover can improve system efficiency, for example, by reducing the number of messages communicated between the target cell 220-b and multiple UEs 115 at the same or similar times.

[0092] A wireless device, such as the network entity 105 and the UE 115-a, may communicate signaling to implement a RACH-free handover from a source cell 220-a to a target cell 220-b via a communication link 205-a. The network entity 105-a may be an example of a satellite having a serving cell 220 (e.g., the source cell 220-a, but it should be understood that any communication described as occurring between two components, such as the source cell 220-a and the UE 115-a, may additionally or alternatively be performed between two other components, such as the target cell 220-b, the UE 115-a, the source cell 220-a, or any combination thereof).

[0093] For example, the network entity 105-a may send a downlink message 215-a to the UE 115-a. The downlink message 215-a may be an example of a request message that includes a request for the UE 115-a to report information for a conditional handover (e.g., a RACH-free handover) using the communication link 205-a. That is, the downlink message 215-a may indicate a request for the UE 115-a to report one or more parameters in the uplink message 210-b (e.g., a report message). For example, the uplink message 210-b may include (e.g., indicate) a differential delay or estimated propagation delay for one or two cells in the cells 220 to provide one or two cells in the cells 220 (e.g., the target cell 220-b) with respect to a future time window (e.g., in accordance with performing the operations described herein). Figure 3 The handover-associated time window), the expected positioning change of UE 115-a based on the current speed, or a combination thereof, and other parameters.

[0094] Thus, the uplink message 210-b may indicate information (e.g., auxiliary information in a report message, such as one or more parameters associated with a cell handover). In some examples, the information (e.g., parameters) indicated by the uplink message 210-b may include a differential delay (e.g., an estimated propagation delay) of the target cell 220-b. Such a delay may indicate a timing difference or difference between the time a signal is sent to the time a signal is received between the UE 115-a and the network entity 105-b (e.g., the difference between the propagation delay associated with the source cell 220-a and the propagation delay associated with the target cell 220-b). In some examples, the propagation delay may be determined based on a reference signal (e.g., the expected time of receiving or sending a signal compared to the actual time of receiving or sending the signal) and a technique for determining such a delay, among others. Additionally or alternatively, the information may include a rate of change for a change in the service link delay (e.g., the rate at which the service link delay is changing for the target cell 220-b and / or the source cell 220-a). The rate of change may be an example of a rate at which a propagation delay is changing over a time period (e.g., a delay may change from a first time delay to a second time delay in a unit amount of time, such as 10 milliseconds / second, although any rate or delay may be used). For example, the rate of change may be a result of the positioning or velocity of the devices relative to each other. The rate of change may be used to estimate the propagation delay of a signal occurring in a future time period (e.g., a time window associated with a handover). In some examples, the information may include an estimated delay or differential delay for the future time window (e.g., during a handover period including an uplink grant for transmitting a handover completion message, the device may calculate an expected delay or a differential delay relative to the source cell 220-a), or a combination thereof. In some examples, one or more of the parameters described herein may correspond to a first time period (e.g., T1 to T2) associated with a future handover time (e.g., a period for performing an upcoming handover procedure), the parameters may correspond to a second time period (e.g., T0 to T1) occurring before the first time period (such as a current time window), or any other time period. For example, the information may include parameters such as an estimated propagation delay for the first time period, the second time period, or both.

[0095] The information may include positioning information, such as UE 115-a positioning, network entity 105 positioning (e.g., satellite positioning), expected positioning of any device (e.g., based on one or more speeds, such as the current UE 115-a speed), speed or acceleration of one or more devices, estimated handover time, and the like.

[0096] In some examples, UE 115-a may be configured to trigger reporting of information (e.g., triggering assistance information) for a handover procedure (e.g., a procedure different from a cell handover) if UE 115-a is at a cell edge, if UE 115-a is mobile, if there is no stored cell handover configuration for a candidate cell (e.g., target cell 220-b), or any combination thereof. Additionally or alternatively, conditions may be configured such that the UE may trigger a handover procedure and indicate associated information, such as if the assistance information was not transmitted before the last report message or the assistance information has changed from the last report message.

[0097] In some examples, the device may determine the cell handover time. As an illustrative example, the device may determine the future handover time based on one or more positioning (e.g., location, ephemeris of the target cell 220-b and / or the source cell 220-a, speed, etc.), beam information, or any combination thereof of these devices. In some examples, the network entity 105 may indicate (e.g., in an RRC message, in a downlink message 215-a) the ephemeris and beam information of the target cell 220-b (e.g., the candidate cell). In other words, the UE 115-a may be provided with the ephemeris and beam information of the candidate cell. In some examples, if the ephemeris and beam information are included in a system information block (SIB), the message (e.g., RRC message) may indicate an index of the network entity 105-b (e.g., a satellite associated with the target cell 220-b). In such an example, the UE 115-a may identify which ephemeris and which beam information of the SIB is used to determine the handover time based on the index.

[0098] The network entity 105-a may send a downlink message 215-b via the communication link 205-a. The downlink message 215-b may be an example of a configuration message. For example, the downlink message 215-b may be an example of a configuration message such as an RRC message or a SIB as described herein.

[0099] In some examples, such as for earth-fixed cells (e.g., cells with borders that do not move or remain relatively stationary when a satellite passes by), the handover time may be aligned with a cell stop time (e.g., the time when the serving cell of UE 115-a stops covering an area including UE 115-a). In some examples, in addition to or as an alternative to various information (e.g., assistance information), UE 115-a may report an estimated handover time. Based on such handover time estimates, the network may provide a time-based cell handover command to UE 115-a. In some examples, such as for earth-mobile cells (e.g., cells with borders that move with the movement of satellites), UE 115-a may determine a future handover time based on the positioning, ephemeris, and beam information of the target cell 220-b.

[0100] In some examples, the downlink message 215-b may include a request for the UE 115-a to provide assistance information corresponding to a time (e.g., T1 to T2). In some examples, in the downlink message 215-a or 215-b or both, the network entity 105-a may request the UE 115-a to perform measurements of one or more synchronization system blocks (SSBs) of the target cell 220-b. In some examples, the network entity 105-a may send information (e.g., assistance information) for performing SSB measurements. For example, such information may include a synchronization system block measurement timing configuration (SMTC), a measurement gap, a measurement time at which the network entity 105-a may avoid scheduling the UE 115-a for any communication, or any combination thereof.

[0101] In some examples, UE 115-a may be configured to provide an up-to-date report close to a potential handover time (e.g., an estimated handover time). For example, UE 115-a may be configured to provide an up-to-date report (e.g., the last report before a handover occurs) using uplink resources indicated by the network (e.g., network entity 105 may provide uplink shared channel resources to UE 115-a to transmit an updated report prior to a time window [T1, T2] in which a handover is scheduled or estimated to occur). In some examples, UE 115-a may indicate a handover time estimate in an uplink message 210-b, and network entity 105-a may receive uplink message 210-b and indicate a time-based handover command to UE 115-a in a downlink message 215-a, 215-b, or 215-c. In some examples, the network may provide a handover command to UE 115-a with an updated value of a timing advance command for the target cell 220-b, K_offset (e.g., the amount of time between a downlink control information message and a scheduled uplink grant opportunity, such as a number of time slots), ephemeris for one or more satellites, and the like.

[0102] In some examples, the source cell 220-a may forward the uplink message 210-b to the target cell 220-b. For example, the source cell 220-a may forward auxiliary information (e.g., one or more parameters described herein, etc.) to the target cell 220-b (e.g., in a handover preparation message, an interface communication extended to include such information, etc.). By conveying such information, for example, in the absence of a RACH procedure, accurate parameters (e.g., timing advance, offset, etc.) can be used for handover and subsequent communications between the UE 115-a and the target cell 220-b to obtain some information at each device.

[0103] In some examples, based on an uplink message 210-b received by the network entity 105-a, the UE 115-a may be configured, for example in a downlink message 215-c (e.g., a configuration message) sent in response to the uplink message 210-b, with a TA to be used for the target cell 220-b within a time window (e.g., from T1 to T2). The TA may indicate the length of time for a signal to travel from a cell (e.g., network entity 105-a or 105-b) to the UE 115-b (or vice versa). In some examples, before T1 and after T2 (e.g., outside a time period associated with a handover operation), the TA may be considered invalid for use. In some such examples, the UE 115-a may initiate a RACH procedure based on the TA being invalid (e.g., based on being outside a time period for a handover operation).

[0104] In some examples, if the calculated TA of UE 115-a changes by a threshold value compared to the configured TA, the UE may determine that the TA is invalid, initiate a RACH, or both. For example, UE 115-a may compare the TA calculated during the time period (e.g., between T1 and T2) with the TA received in the downlink message 215-c (or another message). UE 115-a may initiate a RACH based on the comparison (e.g., if the difference meets a threshold). In some examples, such a threshold or any threshold may be pre-configured at UE 115-a or pre-configured via control signaling (e.g., RRC, MAC-CE, DCI, etc.). In some examples, UE 115-a may use a contention-based four-step RACH or a contention-based two-step RACH (e.g., when no RACH is not possible, for example, due to an invalid TA or other thresholds being met or not met). UE 115-a may or may not be configured with contention-free PRACH resources, resources for RACH-free handover, or both.In some examples, the time-based cell handover execution condition may be changed to a TA-based cell handover execution.

[0105] In some examples, the UE 115-a may indicate the ability to determine that the initial timing error for the TA is within half of the cyclic prefix (CP). If the UE 115-a indicates the ability to determine that the initial timing error for the TA is within half of the CP, the UE 115-a may be configured with one or more handover resources. For example, the one or more handover resources may be one or more resources allocated for performing a RACH-free handover from the source cell 220-a to the target cell 220-b. In some examples, the UE 115-a may determine that the initial timing error for the TA is not within half of the CP, and may release one or more handover resources. After releasing one or more handover resources or one or more RACH-free resources, the UE 115-a may initiate a random access procedure with the target cell 220-b. The UE 115-a may determine whether the global navigation satellite system (GNSS) is updated, and may detect the SSB of the target cell 220-b for synchronization just before or during the time window (e.g., T1 to T2) for the cell handover.

[0106] In some examples, the network entity 105-a may indicate the K_offset parameter value of the target cell 220-b to the UE 115-a in the downlink message 215-c. For example, the downlink message 215-c may provide a common increment (e.g., K_offset = old K_offset + increment). The common increment may be defined accordingly (e.g., the common increment may be defined as new N_TA,common-old N_TA,common). N_TA,common may represent an index corresponding to the value of TA. In some examples, the downlink message 215-c may not include the K_offset of the UE 115-a, and may indicate a K_offset specific to the target cell 220-b. For a reoccurring pre-allocated uplink grant, the first uplink grant opportunity may occur after the condition (e.g., after time slot n+RRC processing time+OFFSET, where n indicates the time slot in which the RRC reconfiguration (HO message) is received from the source, and OFFSET>=K_offset). In some examples, if the difference between the parameter value of K_offset and the value for the specific TA of UE 115-a is greater than a threshold, UE 115-b can be configured to release the pre-allocated uplink grant and initiate a RACH to the target cell 220-b.

[0107] UE 115-a may send an uplink message 210-c to network entity 105-b via communication link 205-b. Uplink message 210-c may indicate a handover message for target cell 220-b. For example, uplink message 210-c may be a handover complete message sent according to various parameters or information described herein. Because such information may be available at both UE 115-a and target cell 220-b before or during the handover, uplink message 210-c may be sent without a RACH procedure.

[0108] In some other examples, UE 115-a may initiate a RACH procedure before sending uplink message 210-c. For example, UE 115-a may send uplink message 210-d to target cell 220-b via communication link 205-b. Uplink message 210-d may initiate a RACH procedure (e.g., uplink message 210-d may be an example of msg1 or msgA). In some examples, initiating a RACH procedure may be based on satisfying one or more thresholds. For example, UE 115-a may initiate RACH based on thresholds such as TA invalidity as described herein (e.g., distance threshold, time period threshold, etc.). As an illustrative example of such a threshold, when target cell 220-b configures UE 115-a with resources for RACH-free handover, UE 115-a may be configured to use RACH under one or more conditions. Under a first condition (e.g., a threshold), the UE may initiate RACH based on a threshold change in TA compared to a cell-specific K_offset. In some examples, the condition may have one or more changes (e.g., a change in elevation angle, a change in RTT, etc.). Under the second condition, if the position of UE 115-a changes by a threshold compared to the last uplink transmission (or the last TA report) to the source cell 220-a, UE 115-a may initiate a RACH. Under the third condition, if a predetermined number of pre-allocated uplink grant opportunities (e.g., based on the HARQ type as described herein) is exceeded, UE 115-a may initiate a RACH, after which UE 115-a may be configured not to use the pre-allocated uplink grant and may initiate a PRACH. Under the fourth condition, if the valid time window defined for UE 115-a to use the pre-allocated uplink grant or to receive the PDCCH for the uplink grant from the target cell 220-b expires, UE 115-a may initiate a RACH. In some examples, although described as initiating RACH based on satisfying one or more thresholds, it should be understood that the UE may initiate RACH based at least in part on not satisfying a threshold, the threshold being satisfied or not satisfied may be greater than or less than a threshold, or a combination thereof.

[0109] In some examples, the device may determine a feedback type (e.g., a HARQ type) of an uplink grant for sending the uplink message 210-c. In some examples, a certain number of configured uplink processes may be configured to determine a HARQ process. As an illustrative example, the device may determine a HARQ process identifier using Equation 1:

[0110]

[0111] In Equation 1, HARQ Process ID may represent a HARQ identifier for the process, CURRENT TTI may represent a current transmission time interval, ulSchedInterval may represent an interval associated with uplink scheduling, and numberofConfULProcesses may represent the number of configured uplink processes for HARQ operation.

[0112] In the NTN, the HARQ process identifier (ID) for the uplink grant may be preconfigured (e.g., using control signaling). In some examples, the number of allowed HARQ processes may or may not be configured. UE 115-a may use the uplink grant for the same transport block size, in other words, for initial transmission or repeated transmission. Such transport block size may include an RRC reconfiguration complete message, a buffer status report (BSR) message, a TA report, an RLC status report message, or any combination thereof. In some examples, the HARQ mode (A or B) may be configured or follow the same as the dynamic grant in the target cell 220-b.

[0113] In some examples, after the initial transmission of the uplink message 210-c, the UE 115-a may be configured to ignore the uplink grant or to continue to repeatedly transmit on the resource at subsequent opportunities (e.g., regardless of the HARQ mode). In some other examples, if the HARQ type is type A, the UE 115-a may ignore the grant while the uplink HARQ RTT timer is running. Additionally or alternatively, if the HARQ type is B, the UE 115-a may be configured to release the pre-allocated grant after the first transmission (e.g., to avoid sending retransmissions at subsequent opportunities). In this case, the target cell 220-b may dynamically schedule retransmissions.

[0114] In some examples, the various messages and parameters described herein may include any number or type of messages. For example, information or parameters described as being indicated in a message may additionally or alternatively be indicated in different messages, different message types, or both. More messages may be used to indicate the information or fewer messages may be used (e.g., a message may include information described as being in separate messages). Messages described as being between two devices may additionally or alternatively be implemented by different devices or in different directions (e.g., an uplink message may also be substituted for an example of a downlink message, and vice versa).

[0115] Figure 3 An example of a timeline 300 supporting techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated. The timeline 300 may include techniques described herein with reference to Figure 2 Examples of Messages and Time Periods In general, timeline 300 may illustrate an example of messaging to support RACH-less handover of UE 115 from a source cell to a target cell as described herein.

[0116] Timeline 300 may include time period 330-a and time period 330-b. Time period 330-a may be a time window between T0 and T1 as described herein. For example, time period 330-a may be an example of a time period that occurs before a handover (e.g., a current time period or near a current time period). Time period 330-b may be an example of a subsequent time window between T1 and T2. Time period 330-b may be an example of a subsequent time window between T1 and T2. Figure 2 The time window associated with the future handover event.

[0117] For example, the device (UE and one or more network entities) may identify an upcoming handover. The device may determine the handover time to occur between the start time of T1 and the end time of T2 (e.g., the handover may occur during at least a portion of the time period 330-b). In some examples, the source cell may send a request message 305. The request message 305 may be an example of a request message (e.g., downlink message 215-a) as described herein. For example, the request message 305 may request the UE to report information associated with a cell handover procedure (e.g., assistance information).

[0118] The UE may send a report message 310 in response to the request message 305. The report message 310 may be an example of a report message (e.g., uplink message 210-a) as described herein. For example, the report message may indicate information (e.g., one or more parameters) such as an estimated propagation delay during the time period 330-b, an estimated propagation delay change rate during the time period 330-b, or other parameters (e.g., as described in reference to FIG. Figure 2The delay or delay change rate, location information, etc. during the time period 330-a).

[0119] The source cell may send a configuration message 315 to the UE in response to the report message 310. For example, the source cell may forward the information to the target cell and configure the TA, the uplink grant timing for sending the handover message 320, or the like as described in reference to FIG. Figure 2 Other parameters as described.

[0120] In some examples, the UE may send a handover message 320 during time period 330-b. For example, the UE may send a handover complete message indicating that the handover was successful based on the communicated auxiliary information (e.g., parameters indicated in one or more messages). The handover message 320 may be sent based on such information (e.g., via a resource usage configured or estimated TA for scheduling of uplink grants). In some other examples, the UE may release resources used for the handover message 320 and instead perform handover based on the information described herein. Figure 2 The RACH procedure is initiated by satisfying (or not satisfying) one or more thresholds.

[0121] Additionally or alternatively, timeline 300 may include additional or alternative messages, the messages may be combined or omitted, the messages may be communicated in different link directions or between different devices, and the like.

[0122] Figure 4 An example of a process flow 400 that supports techniques for handover in a non-terrestrial network in accordance with one or more aspects of the present disclosure is illustrated. Figure 4 105 - d. UE 115 - b may be a reference Figure 1 UE 115 or reference Figure 2 The network entity 105 may be a reference Figure 1 The network entity 105 and the reference Figure 2 In some examples, network entity 105 may be a satellite. Although illustrated as separate satellites for clarity of illustration, it should be understood that the source cell example of network entity 105-c and the target cell example of network entity 105-d may be a single satellite having multiple cells.

[0123] In the following description of process flow 400, operations between UE 115-b and network entity 105 may be sent in a different order than shown, or operations performed by UE 115-b and network entity 105 may be performed in a different order or at a different time. Some operations may also be omitted from process flow 400, or other operations may be added to process flow 400. It should be understood that although UE 115-b and network entity 105 are shown as performing multiple operations of process flow 400, any wireless device may perform the operations shown.

[0124] At 405, a request may be sent from network entity 105-c to UE 115-b. For example, UE 115-b may receive a request from network entity 105-c (e.g., a source cell) requesting UE 115-b to report information for conditional cell handover. In some examples, conditional cell handover may be an example of a cell handover based at least in part on a handover criterion such as time, location, or both. The information may include information such as that described herein with reference to Figure 2 and Figure 3 The one or more parameters may be, for example, a differential delay or an estimated propagation delay of the target cell in a future time window (eg, T1 to T2), a rate of change of the delay, or both.

[0125] At 410, the UE may identify one or more parameters requested by the network entity 105-c in the request message. At 415, the UE 115-b may send a report message as described herein. For example, the message may include an indication of the parameters determined at 410. The message may include information requested by the network entity 105-c indicating the location of the UE, a change in the positioning of the UE, a speed of the UE, a positioning of a first cell (e.g., network entity 105-c), a positioning of a second cell (e.g., network entity 105-d), a cell handover time, one or more delays for one or more time periods, one or more rates of change for the delays, or any combination. The indication of the parameters may be as described herein with reference to Figure 2 An example of the uplink message 210-b is described.

[0126] At 420, the network entity 105-c may send a configuration message to the UE 115-b. The configuration message may be an example of a configuration message, such as a message transmitted in response to the report 415 as described herein. For example, the configuration message may indicate an uplink grant opportunity, a timing advance, etc. for a cell handover message to the network entity 105-d. The configuration message at 420 may be an example of a configuration message, such as a message transmitted in response to the report 415 as described herein. Figure 2 An example of the downlink message 215-b is described.

[0127] At 425, the network entity 105-c may forward the indication of the parameters received from the UE 115-b at 415 to the network entity 105-d. By communicating such information, accurate parameters (e.g., timing advance, offset, etc.) may be used for the handover and subsequent communications between the UE 115-a and the target cell.

[0128] At 430, UE 115-b may determine whether one or more thresholds are met. Figure 2 As described above, the UE 115 - b may determine whether to complete the handover procedure with a handover message or to initiate a RACH procedure with the network entity 105 - d based on whether the threshold is met.

[0129] In some examples, at 435, UE 115-b may send a handover message to the target cell (e.g., network entity 105-d), which may be as described in reference Figure 2 For example, UE 115-b may send a message to the target cell using parameters and resources indicated by configuration message 420 or determined by UE 115-b.

[0130] In some examples, at 440, UE 115-b may initiate a random access channel procedure with network entity 105-d. For example, UE 115-b may determine that one or more thresholds (e.g., as described herein with reference to Figure 2 , TA invalid, etc.). UE 115-b may send a first message of a RACH procedure based on whether a threshold is met or not met. The RACH message at 440 may be as described herein with reference to Figure 2 An example of the uplink message 210-d is described.

[0131] Figure 5 A block diagram 500 of a device 505 supporting techniques for handover in a non-terrestrial network according to one or more aspects of the present disclosure is shown. The device 505 may be an example of aspects of a 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).

[0132] 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, data channels, information channels related to technologies for handover in non-terrestrial networks). The information may be communicated to other components of the device 505. The receiver 510 may utilize a single antenna or a set of multiple antennas.

[0133] 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 (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to technologies for handover in non-terrestrial networks). 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 set of multiple antennas.

[0134] 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 the techniques for handover in a non-terrestrial network 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.

[0135] In some examples, the communication manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit system). The hardware may 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 that is configured to or otherwise supports means for performing the functions described in the present disclosure. In some examples, the 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).

[0136] 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 means for performing the functionality 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.

[0137] In some examples, communication manager 520 may 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 may receive information from receiver 510, transmit information to transmitter 515, or be integrated in conjunction with receiver 510, transmitter 515, or both to obtain information, output information, or perform various other operations as described herein.

[0138] According to the examples disclosed herein, the communication manager 520 may support wireless communication at the UE. For example, the communication manager 520 may be configured to or otherwise support a component for receiving a request for reporting one or more parameters from a first cell, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The communication manager 520 may be configured to or otherwise support a component for sending a message indicating the one or more parameters to the first cell in response to receiving the request. The communication manager 520 may be configured to or otherwise support a component for receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0139] By including or configuring the communication manager 520 according to the examples described herein, the device 505 (e.g., a processor controlling the receiver 510, the transmitter 515, the communication manager 520, or a combination thereof or otherwise coupled thereto) can support techniques for handover in the NTN. For example, these techniques can enable RACH-free handover, which can achieve more efficient utilization of communication resources, improved system efficiency, reduced signaling congestion and overhead, reduced power consumption, or any combination thereof, among other advantages.

[0140] Figure 6 A block diagram 600 of a device 605 supporting techniques for handover in a non-terrestrial network 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).

[0141] 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, data channels, information channels related to technologies for handover in non-terrestrial networks). The information may be communicated to other components of the device 605. The receiver 610 may utilize a single antenna or a set of multiple antennas.

[0142] 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 (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to technologies for handover in non-terrestrial networks). 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 set of multiple antennas.

[0143] Device 605 or its various components may be examples of components for performing various aspects of the techniques for handover in non-terrestrial networks as described herein. For example, communication manager 620 may include handover request component 625, parameter component 630, grant component 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 or otherwise cooperating with receiver 610, transmitter 615, or both. 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.

[0144] According to examples as disclosed herein, the communication manager 620 may support wireless communication at a UE. The handover request component 625 may be configured to or otherwise support a component for receiving a request for reporting one or more parameters from a first cell, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The parameter component 630 may be configured to or otherwise support a component for sending a message indicating the one or more parameters to the first cell in response to receiving the request. The grant component 635 may be configured to or otherwise support a component for receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0145] Figure 7 A block diagram 700 of a communication manager 720 supporting techniques for handover in a non-terrestrial network 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 means for performing various aspects of the techniques for handover in a non-terrestrial network as described herein. For example, the communication manager 720 may include a handover request component 725, a parameter component 730, a grant component 735, a message component 740, a resource component 745, a measurement component 750, a handover time component 755, a timing component 760, a RACH component 765, a feedback component 770, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

[0146] According to examples as disclosed herein, the communication manager 720 may support wireless communication at a UE. The handover request component 725 may be configured to or otherwise support a component for receiving a request for reporting one or more parameters from a first cell, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The parameter component 730 may be configured to or otherwise support a component for sending a message indicating the one or more parameters to the first cell in response to receiving the request. The grant component 735 may be configured to or otherwise support a component for receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0147] In some examples, parameter component 730 can be configured or otherwise support means for sending the message or a second message indicating an estimated propagation delay for a second time period that occurs prior to the time period.

[0148] In some examples, parameter component 730 may be configured to or otherwise support components for sending the message indicating the one or more parameters indicating the location of the UE, a change in positioning of the UE, a speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0149] In some examples, the message component 740 can be configured to or otherwise support a means for receiving a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is based on receiving the second message.

[0150] In some examples, resource component 745 may be configured or otherwise support means for receiving a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring prior to the time period.

[0151] In some examples, measurement component 750 may be configured as or otherwise support means for receiving a second request to perform measurements of synchronization signal blocks of the second cell.

[0152] In some examples, the measurement component 750 can be configured to or otherwise support a means for receiving a second message indicating one or more measurement parameters, the one or more measurement parameters indicating a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof. In some examples, the measurement component 750 can be configured to or otherwise support a means for performing the measurement of the synchronization signal block according to the one or more measurement parameters.

[0153] In some examples, the handover time component 755 can be configured or otherwise support means for determining a handover time associated with the handover of the cell based on the first cell being one of an earth-fixed cell or an earth-mobile cell.

[0154] In some examples, timing component 760 can be configured or otherwise support means for receiving a second message indicating that the timing of the second cell during the time period is advanced.

[0155] In some examples, the timing component 760 can be configured or otherwise support means for determining that a difference between the calculated timing advance and the timing advance indicated by the second message satisfies a threshold. In some examples, the RACH component 765 can be configured or otherwise support means for sending a first message of a random access channel procedure to the second cell based on the satisfied threshold.

[0156] In some examples, RACH component 765 can be configured or otherwise support means for sending a first message of a random access channel procedure to the second cell based on the time period elapsed.

[0157] In some examples, timing component 760 may be configured or otherwise support means for determining whether an initial timing error for timing advance is within half of a cyclic prefix (CP) of the target cell. In some examples, grant component 735 may be configured or otherwise support means for releasing the uplink grant opportunity or handover resource based on determining that the initial timing error is not within half of the CP of the target cell.

[0158] In some examples, feedback component 770 can be configured or otherwise support means for sending one or more messages based on a feedback type associated with the uplink grant opportunity.

[0159] In some examples, parameter component 730 may be configured to or otherwise support means for determining that one or more parameters satisfy one or more thresholds, the one or more parameters including timing advance, the location of the UE, the number of uplink grant opportunities including the uplink grant opportunity, the valid time window associated with the uplink grant opportunity, or any combination thereof. In some examples, RACH component 765 may be configured to or otherwise support means for sending a first message of a random access channel procedure based on the one or more thresholds satisfied.

[0160] Figure 8 A diagram of a system 800 including a device 805 supporting techniques for handover in a non-terrestrial network 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 thereof. 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 in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 845).

[0161] 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.

[0162] 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 that may be capable of concurrently transmitting or receiving multiple wireless transmissions. As described herein, the transceiver 815 may communicate bidirectionally via one or more antennas 825, wired or wireless links. 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.

[0163] 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 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 also include a basic I / O system (BIOS), etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0164] 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) so that the device 805 performs various functions (e.g., functions or tasks that support technologies for handover in non-terrestrial networks). 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.

[0165] According to the examples disclosed herein, the communication manager 820 may support wireless communication at the UE. For example, the communication manager 820 may be configured to or otherwise support a component for receiving a request for reporting one or more parameters from a first cell, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The communication manager 820 may be configured to or otherwise support a component for sending a message indicating the one or more parameters to the first cell in response to receiving the request. The communication manager 820 may be configured to or otherwise support a component for receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0166] By including or configuring the communication manager 820 according to the examples described herein, the device 805 can support techniques for handover in the NTN. For example, these techniques can enable RACH-free handover, which can achieve more efficient utilization of communication resources, improved system efficiency, reduced signaling congestion and overhead, reduced power consumption, or any combination thereof, among other advantages.

[0167] In some examples, the communication manager 820 may 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 may 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 executable by the processor 840 to cause the device 805 to perform various aspects of the techniques for handover in a non-terrestrial network as described herein, or the processor 840 and the memory 830 may be otherwise configured to perform or support such operations.

[0168] Fig. 9 A block diagram 900 of a device 905 supporting techniques for handover in a non-terrestrial network 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).

[0169] 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 communicated 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 fiber) interfaces, wireless interfaces, or any combination thereof.

[0170] The transmitter 915 may provide means for outputting (e.g., sending, 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.

[0171] 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 the techniques for handover in a non-terrestrial network 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.

[0172] 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 system). 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 to or otherwise supports means 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).

[0173] 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 means for performing the functionality 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.

[0174] In some examples, the communication manager 920 may 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 may 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.

[0175] The communication manager 920 may support wireless communication at a network entity associated with a first cell according to an example as disclosed herein. For example, the communication manager 920 may be configured to or otherwise support a component for sending a request to report one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The communication manager 920 may be configured to or otherwise support a component for receiving a message indicating the one or more parameters in response to the sent request. The communication manager 920 may be configured to or otherwise support a component for sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0176] By including or configuring the communication manager 920 according to the examples described herein, the device 905 (e.g., a processor controlling the receiver 910, the transmitter 915, the communication manager 920, or a combination thereof or otherwise coupled thereto) can support techniques for handover in the NTN. For example, these techniques can enable RACH-free handover, which can achieve more efficient utilization of communication resources, improved system efficiency, reduced signaling congestion and overhead, reduced power consumption, or any combination thereof, among other advantages.

[0177] Fig.10 A block diagram 1000 of a device 1005 supporting techniques for handover in a non-terrestrial network 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 the 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).

[0178] 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 communicated to other components of device 1005. In some examples, receiver 1010 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 1010 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof.

[0179] The transmitter 1015 may provide means for outputting (e.g., sending, 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 fiber) 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.

[0180] The device 1005 or its various components may be examples of means for performing various aspects of the techniques for handover in a non-terrestrial network as described herein. For example, the communication manager 1020 may include a handover request manager 1025, a parameter manager 1030, a grant manager 1035, or any combination thereof. The communication manager 1020 may be an example of various aspects of the communication manager 920 as described herein. In some examples, the communication manager 1020 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with the receiver 1010, the transmitter 1015, or both. For example, the communication manager 1020 may receive information from the receiver 1010, transmit information to the transmitter 1015, or be integrated with the receiver 1010, the transmitter 1015, or both to obtain information, output information, or perform various other operations as described herein.

[0181] The communication manager 1020 may support wireless communication at a network entity associated with a first cell according to an example as disclosed herein. The handover request manager 1025 may be configured to or otherwise support a means for sending a request for reporting one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The parameter manager 1030 may be configured to or otherwise support a means for receiving a message indicating the one or more parameters in response to the sent request. The grant manager 1035 may be configured to or otherwise support a means for sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0182] Fig.11A block diagram 1100 of a communication manager 1120 supporting techniques for handover in a non-terrestrial network in accordance with 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 the techniques for handover in a non-terrestrial network as described herein. For example, the communication manager 1120 may include a handover request manager 1125, a parameter manager 1130, a grant manager 1135, a message manager 1140, a resource manager 1145, a measurement manager 1150, a handover time manager 1155, a timing manager 1160, a RACH manager 1165, a feedback manager 1170, or any combination thereof. Each of these components may communicate directly or indirectly with each other (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.

[0183] The communication manager 1120 may support wireless communication at a network entity associated with a first cell according to an example as disclosed herein. The handover request manager 1125 may be configured to or otherwise support a means for sending a request for reporting one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The parameter manager 1130 may be configured to or otherwise support a means for receiving a message indicating the one or more parameters in response to the sent request. The grant manager 1135 may be configured to or otherwise support a means for sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0184] In some examples, parameter manager 1130 may be configured or otherwise support means for receiving the message or a second message indicating an estimated propagation delay for a second time period that occurs prior to the time period.

[0185] In some examples, parameter manager 1130 may be configured to or otherwise support components for receiving the message indicating the one or more parameters, where the one or more parameters indicate the location of the UE, the change in positioning of the UE, the speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0186] In some examples, message manager 1140 may be configured or otherwise support means for sending a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is based on receiving the second message.

[0187] In some examples, resource manager 1145 may be configured or otherwise support means for sending a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring prior to the time period.

[0188] In some examples, measurement manager 1150 may be configured or otherwise support means for sending a second request to perform measurements of synchronization signal blocks of the second cell.

[0189] In some examples, the measurement manager 1150 may be configured to or otherwise support components for sending a second message indicating one or more measurement parameters indicating a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof.

[0190] In some examples, handover time manager 1155 may be configured or otherwise support means for determining a handover time associated with a handover of the cell based on the first cell being one of an earth-fixed cell or an earth-mobile cell.

[0191] In some examples, timing manager 1160 may be configured or otherwise support means for sending a second message indicating that the timing of the second cell during the time period is advanced.

[0192] In some examples, RACH manager 1165 may be configured or otherwise support means for receiving a first message of a random access channel procedure based on a difference between a timing advance of the UE and the timing advance indicated by the second message satisfying a threshold.

[0193] In some examples, RACH manager 1165 may be configured or otherwise support means for receiving a first message of a random access channel procedure based on the time period elapsed.

[0194] In some examples, the message manager 1140 may be configured to or otherwise support a component for receiving an uplink message via the uplink grant opportunity or handover resource based at least in part on an initial timing error for the timing advance not being within one-half of the cyclic prefix (CP) of the target cell.

[0195] In some examples, feedback manager 1170 may be configured or otherwise support means for receiving one or more messages based on a feedback type associated with the uplink grant opportunity.

[0196] In some examples, the RACH manager 1165 may be configured to or otherwise support components for receiving a first message of a random access channel procedure based on one or more parameters satisfying one or more thresholds, the one or more parameters including a timing advance, a location of the UE, a number of uplink grant opportunities including the uplink grant opportunity, a valid time window associated with the uplink grant opportunity, or any combination thereof.

[0197] Fig.12 A diagram of a system 1200 including a device 1205 supporting techniques for handover in a non-terrestrial network 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 thereof. The device 1205 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, which 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 receive 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).

[0198] 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 that may be capable of (e.g., concurrently) sending or receiving wireless transmissions. The transceiver 1210 may also include a modem for modulating a signal, for providing the modulated signal for transmission (e.g., via one or more antennas 1215, via a wired transmitter), for receiving the modulated signal (e.g., from one or more antennas 1215, from a wired receiver), and for demodulating a signal. 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 communications via one or more communication links (e.g., communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0199] 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 system memory or another type of memory). In some cases, the code 1230 may not be directly executable by the processor 1235, but (for example, when compiled and executed) may cause the computer to perform the functions described herein. In some cases, the memory 1225 may also include a BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0200] 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., memory 1225) so that the device 1205 performs various functions (e.g., functions or tasks that support technologies for handover in non-terrestrial networks). 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. Processor 1235 can be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software (such as an operating system, virtual machine, or container instance)) that can host (e.g., by executing code 1230) functionality for performing the functions of device 1205.

[0201] In some examples, bus 1240 may support communications of protocol layers (e.g., within protocol layers) of a protocol stack. In some examples, bus 1240 may support communications associated with logical channels of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within components 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 of the different components or divided between the different components).

[0202] In some examples, communication manager 1220 may manage aspects of communications with core network 130 (e.g., via one or more wired or wireless backhaul links). For example, communication manager 1220 may manage delivery of data communications for client devices, such as one or more UEs 115. In some examples, communication manager 1220 may manage communications with other network entities 105 and may include a controller or scheduler for controlling communications with UE 115 in collaboration with other network entities 105. In some examples, communication manager 1220 may support an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between network entities 105.

[0203] The communication manager 1220 may support wireless communication at a network entity associated with a first cell according to an example as disclosed herein. For example, the communication manager 1220 may be configured to or otherwise support a component for sending a request to report one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The communication manager 1220 may be configured to or otherwise support a component for receiving a message indicating the one or more parameters in response to the sent request. The communication manager 1220 may be configured to or otherwise support a component for sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0204] By including or configuring the communication manager 1220 according to the examples described herein, the device 1205 can support techniques for handover in the NTN. For example, these techniques can enable RACH-free handover, which can achieve more efficient utilization of communication resources, improved system efficiency, reduced signaling congestion and overhead, reduced power consumption, or any combination thereof, among other advantages.

[0205] In some examples, the communication manager 1220 may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with the transceiver 1210, one or more antennas 1215 (e.g., where applicable), or any combination thereof. 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 may 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 executable by the processor 1235 to cause the device 1205 to perform various aspects of the techniques for handover in a non-terrestrial network as described herein, or the processor 1235 and the memory 1225 may be otherwise configured to perform or support such operations.

[0206] Fig.13 A flow chart illustrating a method 1300 of supporting techniques for handover in a non-terrestrial network 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 components thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE or components thereof as described in reference to Figures 1 to 8The UE 115 described above may be executed. In some examples, the UE may execute a set of instructions 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.

[0207] At 1305, the method may include: receiving a request from a first cell to report one or more parameters, the one or more parameters associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. 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 handover request component 725 is used to execute.

[0208] At 1310, the method may include: in response to receiving the request, sending a message indicating the one or more parameters to the first cell. The operations of 1310 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1310 may be performed as described in reference to Figure 7 The parameter component 730 is used to perform.

[0209] At 1315, the method may include: receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period. 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 grant component 735 is executed.

[0210] Fig.14 A flow chart illustrating a method 1400 of supporting techniques for handover in a non-terrestrial network according to one or more aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE or components thereof as described herein. Figures 1 to 8 The UE 115 described above may be executed. In some examples, the UE may execute a set of instructions 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.

[0211] At 1405, the method may include: receiving a request from a first cell to report one or more parameters associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. 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 Figure 7 The handover request component 725 is used to execute.

[0212] At 1410, the method may include: in response to receiving the request, sending a message to the first cell indicating the one or more parameters. The operations of 1410 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1410 may be performed as described in reference Figure 7 The parameter component 730 is used to perform.

[0213] At 1415, the method may include sending the message or a second message indicating an estimated propagation delay for a second time period that occurs before the time period. The operations of 1415 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1415 may be performed as described in reference to Figure 7 The parameter component 730 is used to perform.

[0214] At 1420, the method may include: receiving an indication of an uplink grant opportunity from the first cell based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period. The operations of 1420 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1420 may be performed as described in reference to Figure 7 The grant component 735 is executed.

[0215] Fig.15 A flow chart illustrating a method 1500 of supporting techniques for handover in a non-terrestrial network according to one or more aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1500 may be implemented by a network entity or a component thereof as described in reference to Figures 1 to 4 as well as Figures 9 to 12 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.

[0216] At 1505, the method may include: sending a request to report one or more parameters associated with a cell handover of the UE from the first cell to the second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The operations of 1505 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1505 may be performed as described in reference to Fig.11 The handover request manager 1125 is used to perform the above operation.

[0217] At 1510, the method may include receiving a message indicating the one or more parameters in response to the sent request. The operations of 1510 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1510 may be performed as described in reference to Fig.11 The parameter manager 1130 is used to execute.

[0218] At 1515, the method may include: sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period. The operations of 1515 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1515 may be performed as described in reference to Fig.11 The grant manager 1135 is used to execute.

[0219] Fig.16 A flow chart illustrating a method 1600 of supporting techniques for handover in a non-terrestrial network according to one or more aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1600 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 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.

[0220] At 1605, the method may include: sending a request to report one or more parameters associated with a cell handover of the UE from the first cell to the second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, an estimated propagation delay change rate between the UE and the second cell during the time period, or both. The operations of 1605 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed as described in reference to Fig.11 The handover request manager 1125 is used to perform the above operation.

[0221] At 1610, the method may include receiving a message indicating the one or more parameters in response to the sent request. The operations of 1610 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1610 may be performed as described in reference to Fig.11 The parameter manager 1130 is used to execute.

[0222] At 1615, the method may include receiving the message or a second message indicating an estimated propagation delay for a second time period that occurs before the time period. The operations of 1615 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed as described in reference to Fig.11 The parameter manager 1130 is used to execute.

[0223] At 1620, the method may include: sending an indication of an uplink grant opportunity based on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period. The operations of 1620 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1620 may be performed as described in reference to Fig.11 The grant manager 1135 is used to execute.

[0224] The following provides an overview of various aspects of the disclosure:

[0225] Aspect 1: A method for performing wireless communications at a UE, the method comprising: receiving a request from a first cell to report one or more parameters, the one or more parameters being associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of the estimated propagation delay between the UE and the second cell during the time period, or both; sending a message indicating the one or more parameters to the first cell in response to receiving the request; and receiving an indication of an uplink grant timing from the first cell based at least in part on the one or more parameters, the uplink grant timing being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0226] Aspect 2: The method according to aspect 1, further comprising: sending the message or a second message indicating an estimated propagation delay of a second time period, the second time period occurring before the time period.

[0227] Aspect 3: According to the method described in any one of Aspects 1 to 2, the method further includes: sending the message indicating the one or more parameters, wherein the one or more parameters indicate the position of the UE, the positioning change of the UE, the speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0228] Aspect 4: According to any one of Aspects 1 to 3, the method also includes: receiving a second message or the request indicating the ephemeris of the second cell, the timing advance associated with the second cell, the time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is at least partially based on receiving the second message.

[0229] Aspect 5: According to the method according to any one of aspects 1 to 4, the method further includes: receiving a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

[0230] Aspect 6: According to the method according to any one of Aspects 1 to 5, the method also includes: receiving a second request to perform measurement of the synchronization signal block of the second cell.

[0231] Aspect 7: According to the method described in Aspect 6, the method also includes: receiving a second message indicating one or more measurement parameters, wherein the one or more measurement parameters indicate a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof; and performing the measurement of the synchronization signal block according to the one or more measurement parameters.

[0232] Aspect 8: The method according to any one of aspects 1 to 7, the method further comprising: determining a handover time associated with the cell handover based at least in part on the first cell being one of an earth fixed cell or an earth mobile cell.

[0233] Aspect 9: According to the method according to any one of aspects 1 to 8, the method further includes: receiving a second message indicating that the timing of the second cell for the time period is advanced.

[0234] Aspect 10: According to the method according to Aspect 9, the method also includes: determining that the difference between the calculated timing advance and the timing advance indicated by the second message satisfies a threshold; and sending a first message of the random access channel procedure to the second cell at least in part based on the satisfied threshold.

[0235] Aspect 11: The method according to any one of aspects 1 to 10, the method further comprising: sending a first message of a random access channel procedure to the second cell based at least in part on the lapse of the time period.

[0236] Aspect 12: According to the method described in any one of Aspects 1 to 11, the method also includes: determining whether the initial timing error for the timing advance is within half of the cyclic prefix (CP) of the target cell; and releasing the uplink grant opportunity or handover resource based at least in part on determining that the initial timing error is not within half of the CP of the target cell.

[0237] Aspect 13: The method according to any one of aspects 1 to 12, the method further comprising: sending one or more messages according to a feedback type associated with the uplink grant opportunity.

[0238] Aspect 14: According to the method described in any one of Aspects 1 to 13, the method further includes: determining that one or more parameters satisfy one or more thresholds, the one or more parameters including timing advance, the position of the UE, the number of uplink grant opportunities including the uplink grant opportunity, the valid time window associated with the uplink grant opportunity, or any combination thereof; and sending a first message of a random access channel procedure based at least in part on the one or more thresholds satisfied.

[0239] Aspect 15: A method for performing wireless communications at a network entity associated with a first cell, a second cell, or both, the method comprising: sending a request for reporting one or more parameters, the one or more parameters being associated with a cell handover of a UE from the first cell to the second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; receiving a message indicating the one or more parameters in response to the sent request; and sending an indication of an uplink grant timing based at least in part on the one or more parameters, the uplink grant timing being associated with the cell handover from the first cell to the second cell to be performed during the time period.

[0240] Aspect 16: The method according to aspect 15, the method further comprising: receiving the message or a second message indicating an estimated propagation delay for a second time period, the second time period occurring before the time period.

[0241] Aspect 17: According to the method described in any one of Aspects 15 to 16, the method also includes: receiving the message indicating the one or more parameters, wherein the one or more parameters indicate the position of the UE, the positioning change of the UE, the speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

[0242] Aspect 18: According to any one of Aspects 15 to 17, the method also includes: sending a second message or the request indicating the ephemeris of the second cell, the timing advance associated with the second cell, the time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is at least partially based on receiving the second message.

[0243] Aspect 19: According to the method according to any one of aspects 15 to 18, the method further includes: sending a second message indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

[0244] Aspect 20: According to the method according to any one of Aspects 15 to 19, the method further includes: sending a second request to perform measurement of the synchronization signal block of the second cell.

[0245] Aspect 21: According to the method according to Aspect 20, the method also includes: sending a second message indicating one or more measurement parameters, wherein the one or more measurement parameters indicate a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof.

[0246] Aspect 22: The method according to any one of aspects 15 to 21, the method further comprising: determining a handover time associated with the cell handover based at least in part on the first cell being one of an earth fixed cell or an earth mobile cell.

[0247] Aspect 23: According to the method according to any one of aspects 15 to 22, the method further includes: sending a second message indicating that the timing of the second cell for the time period is advanced.

[0248] Aspect 24: The method according to aspect 23 further comprises: receiving a first message of a random access channel procedure based at least in part on the difference between the timing advance of the UE and the timing advance indicated by the second message satisfying a threshold.

[0249] Aspect 25: The method according to any one of aspects 15 to 24, the method further comprising: receiving a first message of a random access channel procedure based at least in part on the time period lapse.

[0250] Aspect 26: According to any one of Aspects 15 to 25, the method also includes: being unable to receive an uplink message via the uplink grant opportunity or handover resource, at least in part based on the initial timing error for the timing advance being not within half of the cyclic prefix (CP) of the target cell.

[0251] Aspect 27: The method according to any one of aspects 15 to 26, the method further comprising: receiving one or more messages according to a feedback type associated with the uplink grant opportunity.

[0252] Aspect 28: According to any one of Aspects 15 to 27, the method also includes: receiving a first message of a random access channel procedure based at least in part on one or more parameters satisfying one or more thresholds, the one or more parameters including timing advance, the position of the UE, the number of uplink grant opportunities including the uplink grant opportunity, the valid time window associated with the uplink grant opportunity, or any combination thereof.

[0253] Aspect 29: An apparatus for performing wireless communications at a UE, the apparatus 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.

[0254] Aspect 30: An apparatus for wireless communication at a UE, the apparatus comprising: at least one means for performing the method according to any one of aspects 1 to 14.

[0255] Aspect 31: 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 the method according to any one of aspects 1 to 14.

[0256] Aspect 32: An apparatus for wireless communication at a network entity associated with a first cell, the apparatus 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 28.

[0257] Aspect 33: An apparatus for wireless communication at a network entity associated with a first cell, the apparatus comprising at least one means for performing a method according to any one of aspects 15 to 28.

[0258] Aspect 34: A non-transitory computer-readable medium storing code for wireless communication at a network entity associated with a first cell, the code comprising instructions executable by a processor to perform a method according to any one of aspects 15 to 28.

[0259] 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.

[0260] 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.

[0261] The information and signals described herein may be represented using any of a variety of different technologies and techniques. 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.

[0262] 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, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0263] 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 the present 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 functions are implemented at different physical locations.

[0264] Computer-readable medium includes both non-transient computer storage medium and communication medium, and the communication medium includes any medium that promotes the transfer of computer program 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 components and any other non-transient medium that can be accessed by general or special-purpose computer or general or special-purpose processor in the form of instruction or data structure.In addition, 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, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are included in the definition of computer-readable medium. Disks and optical disks used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, and magnetic disks can reproduce data magnetically and optical discs can reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0265] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with 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, for example, 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."

[0266] The terms "determine" or "determining" encompass a variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure), ascertaining, etc. Additionally, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data stored in a memory), etc. Additionally, "determining" may include parsing, retrieving, selecting, choosing, establishing, and other such similar actions.

[0267] 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.

[0268] 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 specific implementation includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0269] 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. Thus, 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. A method for wireless communication at a user equipment (UE), the method comprising: receiving, from a first cell, a request to report one or more parameters associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; sending a message indicating the one or more parameters to the first cell in response to receiving the request; as well as An indication of an uplink grant opportunity is received from the first cell based at least in part on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

2. The method according to claim 1, further comprising: The message or a second message indicating an estimated propagation delay for a second time period occurring before the time period is sent.

3. The method according to claim 1, further comprising: The message is sent indicating the one or more parameters, wherein the one or more parameters indicate the location of the UE, a change in the positioning of the UE, a speed of the UE, the positioning of the first cell, the positioning of the second cell, or any combination thereof.

4. The method according to claim 1, further comprising: receiving a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is based at least in part on receiving the second message.

5. The method according to claim 1, further comprising: A second message is received indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

6. The method according to claim 1, further comprising: A second request to perform measurements of synchronization signal blocks of the second cell is received.

7. The method according to claim 6, further comprising: receiving a second message indicating one or more measurement parameters, the one or more measurement parameters indicating a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof; as well as The measuring of the synchronization signal block is performed according to the one or more measurement parameters.

8. The method according to claim 1, further comprising: A handover time associated with the cell handover is determined based at least in part on the first cell being one of an earth-fixed cell or an earth-mobile cell.

9. The method according to claim 1, further comprising: A second message is received indicating that the timing of the second cell for the time period is advanced.

10. The method according to claim 9, further comprising: determining that a difference between a calculated timing advance and the timing advance indicated by the second message satisfies a threshold; as well as A first message of a random access channel procedure is sent to the second cell based at least in part on the satisfied threshold.

11. The method according to claim 1, further comprising: A first message of a random access channel procedure is sent to the second cell based at least in part on the lapse of the time period.

12. The method according to claim 1, further comprising: determining whether an initial timing error for the timing advance is within half of a cyclic prefix (CP) of the target cell; as well as The uplink grant opportunity or handover resources are released based at least in part on determining that the initial timing error is not within one-half of the CP of the target cell.

13. The method according to claim 1, further comprising: One or more messages are sent according to a feedback type associated with the uplink grant opportunity.

14. The method according to claim 1, further comprising: determining that one or more parameters satisfy one or more thresholds, the one or more parameters comprising a timing advance, a location of the UE, a number of uplink grant opportunities including the uplink grant opportunity, a valid time window associated with the uplink grant opportunity, or any combination thereof; and A first message of a random access channel procedure is sent based at least in part on the one or more thresholds being satisfied.

15. A method for wireless communication at a network entity associated with a first cell, a second cell, or both, the method comprising: sending a request for reporting one or more parameters associated with a cell handover of a user equipment (UE) from the first cell to the second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; receiving a message indicating the one or more parameters in response to the sent request; as well as An indication of an uplink grant opportunity is sent based at least in part on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

16. The method according to claim 15, further comprising: The message or a second message indicating an estimated propagation delay for a second time period occurring before the time period is received.

17. The method according to claim 15, further comprising: The message is received indicating the one or more parameters, wherein the one or more parameters indicate a location of the UE, a change in positioning of the UE, a speed of the UE, a positioning of the first cell, a positioning of the second cell, or any combination thereof.

18. The method according to claim 15, further comprising: and sending a second message or the request indicating ephemeris of the second cell, a timing advance associated with the second cell, a time offset associated with the second cell, or any combination thereof, wherein sending the message indicating the one or more parameters is based at least in part on receiving the second message.

19. The method according to claim 15, further comprising: A second message is sent indicating uplink resources for transmitting a report to the first cell, the uplink resources occurring before the time period.

20. The method according to claim 15, further comprising: Sending a second request to perform measurements of synchronization signal blocks of the second cell.

21. The method according to claim 20, further comprising: A second message indicating one or more measurement parameters is sent, wherein the one or more measurement parameters indicate a synchronization signal block measurement timing configuration, a measurement gap, a measurement time, or a combination thereof.

22. The method according to claim 15, further comprising: A handover time associated with the cell handover is determined based at least in part on the first cell being one of an earth-fixed cell or an earth-mobile cell.

23. The method according to claim 15, further comprising: A second message is sent indicating that the timing of the second cell for the time period is advanced.

24. The method according to claim 23, further comprising: A first message of a random access channel procedure is received based at least in part on a difference between a timing advance of the UE and the timing advance indicated by the second message satisfying a threshold.

25. The method according to claim 15, further comprising: A first message of a random access channel procedure is received based at least in part on the lapse of the time period.

26. The method according to claim 15, further comprising: An uplink message cannot be received via the uplink grant opportunity or handover resource based at least in part on an initial timing error for the timing advance not being within one-half of a cyclic prefix (CP) of the target cell.

27. The method according to claim 15, further comprising: One or more messages are received according to a feedback type associated with the uplink grant opportunity.

28. The method of claim 15, further comprising: A first message of a random access channel procedure is received based at least in part on one or more parameters satisfying one or more thresholds, the one or more parameters including a timing advance, a location of the UE, a number of uplink grant opportunities including the uplink grant opportunity, a valid time window associated with the uplink grant opportunity, or any combination thereof.

29. An apparatus for wireless communication at a user equipment (UE), the apparatus 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, from a first cell, a request to report one or more parameters associated with a cell handover of the UE from the first cell to a second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; sending a message indicating the one or more parameters to the first cell in response to receiving the request; as well as An indication of an uplink grant opportunity is received from the first cell based at least in part on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

30. An apparatus for wireless communication at a network entity associated with a first cell, a second cell, or both, the apparatus 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 a request for reporting one or more parameters associated with a cell handover of a user equipment (UE) from the first cell to the second cell to be performed during a time period, the one or more parameters indicating an estimated propagation delay between the UE and the second cell during the time period, a rate of change of an estimated propagation delay between the UE and the second cell during the time period, or both; receiving a message indicating the one or more parameters in response to the sent request; as well as An indication of an uplink grant opportunity is sent based at least in part on the one or more parameters, the uplink grant opportunity being associated with the cell handover from the first cell to the second cell to be performed during the time period.

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