Method for non-terrestrial network handover enhancement in wireless communications

Abstract

Various solutions for non-terrestrial network (NTN) handover enhancements in wireless communications are described. A device may report very small aperture terminal (VSAT) user equipment (UE) capability information to a first network node that includes a first satellite. The device may then receive a handover command from the first network node. The handover command may indicate a handover from the first network node to a second network node comprising a second satellite. The device may also redirect the very small aperture terminal antenna to the second satellite for a very small aperture terminal antenna redirection duration, and perform a switch after the very small aperture terminal antenna redirection duration.

Description

[0001] Cross-referencing

[0002] This disclosure is part of a non-provisional application that claims priority to U.S. Provisional Patent Application No. 63 / 587,760 (filed October 4, 2023), the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to wireless communications, and more specifically, to handover enhancements for very small aperture terminal (VSAT) user equipment (UE) and network nodes in non-terrestrial networks (NTNs) in wireless communications. Background Technology

[0004] Unless otherwise stated herein, the methods described in this section are not prior art to the claims and are not recognized as prior art because they are included in this section.

[0005] In the 3rd generation partnership program (3 rd In Release 17 of the Generation Partnership Project (3GPP), Non-Terrestrial Networks (NTN) were introduced as a terminal-to-satellite direct communication technology based on the New Radio (NR) interface. With the integration of satellite networks and terrestrial cellular networks (e.g., 5G...),... th With the convergence of Generation 5G (5G) networks, NTN can provide ubiquitous coverage unrestricted by terrain and topography. As NTN continues to evolve in the 5G-Advanced phase, it has become an important component of the 3GPP Release 18 work plan. Currently, NTN can include two working groups: Internet-of-Things (IoT) NTN and New Radio (NR) NTN. IoT NTN focuses on supporting satellite IoT services for user devices with enhanced machine-type communication (eMTC) and narrowband IoT (NB-IoT). NR NTN utilizes the 5G NR framework to enable direct connectivity between satellites and smartphones to provide voice and data services.

[0006] For satellite communications, user equipment (UEs) may require large antennas or phased arrays to meet link budget requirements; these UEs are known as Very Small Aperture Terminal User Equipment (VSAT UEs). In non-terrestrial networks, because satellites are mobile, VSAT UEs may need to perform handovers (e.g., from a source satellite to a target satellite) to ensure normal transmission and reception over long connection periods and to avoid radio link failures. For example, redirecting the VSAT antenna to the target satellite can introduce significant delays measured in seconds or even tens of seconds. However, the handover mechanism in the current 3GPP Release 18 standard does not account for this redirection delay. Therefore, the physical random access channel (PRACH) resources of the UE during initial access to the target satellite will be reserved for an extended period. Furthermore, because the handover-related timers are not adapted for satellite scenarios, the UE's operations during handover may not be executed correctly (e.g., the UE may not have enough time to complete the handover).

[0007] Therefore, optimizing handover mechanisms for satellite scenarios has become a crucial issue for modern wireless communication systems. Consequently, it is necessary to provide appropriate solutions to address these problems.

[0008] Therefore, it is necessary to provide appropriate schemes and designs for allowing user devices and networks to perform satellite handover procedures in mobile communications. Summary of the Invention

[0009] The following content is for illustrative purposes only and is not intended to be limiting in any way. That is, the following content is intended to introduce the concepts, key points, benefits, and advantages of the novel and non-obvious techniques described herein. Some embodiments will be further elaborated in the detailed description below. Therefore, the following content is not intended to identify the essential features of the claimed subject matter, nor is it intended to determine the scope of the claimed subject matter.

[0010] One objective of this disclosure is to propose schemes, concepts, designs, systems, methods, and apparatuses related to enhanced handover of non-terrestrial networks (NTNs) in wireless communications. It is believed that by implementing one or more of the schemes proposed herein, the aforementioned problems can be avoided or mitigated.

[0011] In one aspect, a method may involve a device reporting very small aperture end-user equipment (MSE) capability information to a first network node, wherein the first network node includes or is associated with a first satellite. The method may also involve the device receiving a handover command from the first network node, wherein the handover command indicates a handover from the first network node to a second network node that includes or is associated with a second satellite. The method may further involve the device redirecting a very small aperture end-user equipment (MSE) antenna to the second satellite during an MSE antenna redirection period. The method may also involve the device performing a handover after the MSE antenna redirection period has elapsed.

[0012] In one aspect, a method may involve a first network node receiving very small aperture end-user equipment (VFA) capability information from a device, wherein the first network node includes or is associated with a first satellite. The method may also involve the first network node sending a handover command to the device based on the VFA capability information, wherein the handover command indicates a handover from the first network node to a second network node that includes or is associated with a second satellite.

[0013] It is worth noting that, although the content described herein may be set against the backdrop of certain wireless access technologies, networks, and network topologies, such as Long-Term Evolution (LTE), LTE-Advanced, LTE-AdvancedPro, 5G, New Radio (NR), Internet of Things (IoT) and Narrowband Internet of Things (NB-IoT), Industrial Internet of Things (IIoT), Beyond 5G (B5G), and 6th Generation (6G), the concepts, schemes, and any variations / derivatives thereof proposed can be implemented, used, and realized in other types of wireless access technologies, networks, and network topologies. Therefore, the scope of this disclosure is not limited to the examples described herein. Attached Figure Description

[0014] The accompanying drawings are intended to further understand this disclosure and are incorporated into and constitute a part of this disclosure. The drawings illustrate embodiments of this disclosure and, together with the description, serve to explain the principles of this disclosure. It will be understood that the drawings are not necessarily drawn to scale, as some components may be shown out of proportion to actual dimensions in order to clearly illustrate the concepts of this disclosure.

[0015] Figure 1 This is an illustration depicting an example scenario of a very small aperture end-user device switching from one satellite to another, according to this disclosure.

[0016] Figure 2 This is a diagram illustrating example scenarios of communication environments in which various solutions and schemes can be implemented according to this disclosure.

[0017] Figure 3 This is an illustration depicting an example scenario of an enhanced handover process for a non-terrestrial network according to an embodiment of this disclosure.

[0018] Figure 4 This is an illustration depicting an example scenario of an enhanced handover process for a non-terrestrial network according to another embodiment of this disclosure.

[0019] Figure 5 This is an illustration depicting an example scenario of an enhanced handover process for a non-terrestrial network according to another embodiment of this disclosure.

[0020] Figure 6 This is an illustration depicting an example scenario of an enhanced handover process for a non-terrestrial network according to another embodiment of this disclosure.

[0021] Figure 7 This is a block diagram illustrating an example communication system according to an embodiment of this disclosure.

[0022] Figure 8 This is a flowchart illustrating an example process according to an embodiment of this disclosure.

[0023] Figure 9 This is a flowchart illustrating another example flow according to an implementation of this disclosure. Detailed Implementation

[0024] Detailed embodiments and implementations of the claimed subject matter are disclosed herein. However, it should be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter, which can be embodied in various forms. This disclosure can be embodied in many different forms and should not be construed as being limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided to make the description of this disclosure exhaustive and complete, and to fully communicate the scope of this disclosure to those skilled in the art. In the following description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0025] Overview

[0026] According to embodiments of this disclosure, various techniques, methods, schemes, and / or solutions related to enhanced handover of non-terrestrial networks (NTNs) in wireless communications are involved. According to this disclosure, multiple possible solutions can be implemented individually or in combination. That is, although these possible solutions are described separately below, two or more possible solutions can be implemented in some combination.

[0027] In this disclosure, non-terrestrial networks (NTNs) refer to networks that utilize radio frequency (RF) and information processing resources carried by high-Earth orbit, medium-Earth orbit, low-Earth orbit satellites, or other high-altitude communication platforms to provide communication services to user equipment (UEs). Depending on the payload capabilities of the satellite, there are two typical scenarios: transparent payloads and regenerative payloads. In transparent payload mode, the satellite does not process the signals and waveforms in the communication service but only acts as an RF amplifier to forward data. In regenerative payload mode, in addition to RF amplification, the satellite also possesses processing capabilities such as modulation / demodulation, encoding / decoding, switching, and routing. It is worth noting that the motivation for this disclosure stems from, but is not limited to, the NTN scenario.

[0028] In NTN, due to the motion of satellites, Very Small Aperture End User Equipment (VSAT UE) may need to perform handovers (e.g., from a source satellite to a target satellite) to ensure normal transmission and reception during long connection periods and avoid radio link failures. To prepare for the handover, the VSAT UE needs to reorient its VSAT antenna to the target satellite, which can introduce significant delays measured in seconds or even tens of seconds. For example, when the VSAT UE uses a mechanically oriented antenna, the rotor speed required to move the antenna may be 2 to 10 degrees per second. Figure 1 This document illustrates an example scenario 100 of a Very Small Aperture End User Equipment (VSA) switching from one satellite to another, according to this disclosure. Scenario 100 involves a VSA initially communicating wirelessly with satellite 1 (denoted as SAT#1). Subsequently, as the satellite moves over time, the area where the VSA is located will no longer be served by satellite 1, but by satellite 2 (denoted as SAT#2). To ensure normal transmission and reception and avoid radio link failure, the VSA needs to perform a handover, switching the communication link from satellite 1 to satellite 2. Therefore, before performing the handover, the VSA needs to redirect its VSA antenna to satellite 2 with a redirection delay.

[0029] It is important to note that the current handover mechanism in 3GPP Release 18 did not account for redirection delays. Therefore, PRACH resources initially accessed by the user equipment on the target satellite will be retained for a longer period. Furthermore, because the handover-related timers are not adapted to the satellite scenario, user equipment operations during the handover process may not execute correctly (e.g., the user equipment may not have enough time to complete the handover).

[0030] In view of the above, this disclosure proposes several schemes related to NTN handover enhancement in wireless communication. Figure 2Example scenario 200 of communication environments in which various solutions and schemes can be implemented according to this disclosure is illustrated. Scenario 200 involves user equipment 210 (e.g., a very small aperture terminal user equipment) wirelessly communicating with network 220 (e.g., a wireless network including NTN and terrestrial network (TN)) through one or more terrestrial network nodes 221 to 222 (e.g., base stations (BS), such as evolved Node-B (eNB), gNB, or transmission / reception point (TRP)) and one or more non-terrestrial network nodes 223 to 224 (e.g., satellites). In some embodiments, terrestrial network node 221 and non-terrestrial network node 223 may form an NTN serving cell to wirelessly communicate with user equipment 210. Similarly, terrestrial network node 222 and non-terrestrial network node 224 may form an NTN serving cell to wirelessly communicate with user equipment 210. Alternatively, non-terrestrial network nodes 223 / 224 may have built-in base station functionality to form an NTN serving cell to wirelessly communicate with user equipment 210 without involving any base station. In such Figure 2 In the communication environment shown, user equipment 210, terrestrial network nodes 221 to 222, and non-terrestrial network nodes 223 to 224 can implement various schemes related to NTN handover enhancement in wireless communication according to this disclosure, as described below. It is worth noting that although the various proposed schemes may be described separately or individually below, in practice, some or all of the proposed schemes may be used in combination or implemented. Of course, each proposed scheme may also be used or implemented individually.

[0031] According to the first embodiment of this disclosure, the Very Small Aperture (VSA) terminal user equipment (MSU) can report its capability information to the source network node. Specifically, the MSA capability information includes information that enables the source network node to understand the time required to orient the MSA antenna from the source satellite to the target satellite, so that the source network node can initiate a handover procedure based on the MSA capability information. Therefore, the MSA can orient its antenna to the target satellite during the reorientation period and perform a handover after the reorientation period ends.

[0032] In some implementations, the very small aperture (VSA) terminal user equipment (MSU) capability information may include at least the VSA antenna type, indicating that the MSA uses an electronic or mechanical directional antenna. Additionally or optionally, the MSA capability information may include the ability to receive signals from multiple satellites simultaneously (e.g., using multiple user equipment beams or multiple MSA antennas or phased array antennas), and / or the ability to maintain a link with the source network node or satellite during the MSA antenna reorientation duration (e.g., for electronic directional antennas). For example, the MSA may report its capability information during a user equipment capability transfer procedure. The capability transfer procedure may be initiated by a UECapabilityEnquiry message from the source network node. Upon receiving the UECapabilityEnquiry message, the MSA may reply to the source network node via a UECapabilityInformation message containing the MSA capability information.

[0033] In some implementations, the Minimum Aperture Terminal Equipment (VAE) capability information may include a parameter related to the VAE antenna reorientation duration. In Option 1, this parameter may indicate the rotor speed (e.g., degrees per second), which the source network node may calculate using approximate VAE locations and the positions of the source and target satellites. In Option 2, this parameter may indicate a numerical value for the VAE antenna reorientation duration; for example, the VAE may calculate the VAE antenna reorientation duration using the positions of the source and target satellites and report the calculated duration plus a certain margin (depending on other overhead) to the source network node. Option 2 may be applicable for electronically directional antennas (e.g., phased arrays) because the orientation process may require preparation and activation time. Additionally or optionally, this parameter may indicate at least one of: (i) the VAE antenna reorientation time class, such as long, medium, or short; (ii) the minimum VAE antenna reorientation time (e.g., for a predefined reorientation angle); and (iii) the maximum VAE antenna reorientation time (e.g., for a predefined reorientation angle).

[0034] In some implementations, the Very Small Aperture End User Equipment (VSA) may request the reporting of parameters related to the VSA antenna reorientation duration upon network request. For example, the source network node may send a request message (e.g., a handover command) containing auxiliary information to the VSA. The auxiliary information may include ephemeris information, epoch time, and the service start time of the target satellite, enabling the VSA to estimate / determine the numerical value of the VSA antenna reorientation duration based on the auxiliary information. The VSA can then respond to the request message by reporting the estimated value to the source network node.

[0035] In the second proposed scheme of this disclosure, a new timer (e.g., referred to as a redirection timer or offset timer) can be introduced to handle the redirection time of the very small aperture terminal antenna. This new timer can be triggered at the start of the handover procedure on the user equipment (UE) side (e.g., starting a new timer upon receiving a handover command), and the UE will not perform initial access to the target satellite (e.g., PRACH transmission) until the new timer expires. On the UE side, the initiation of the handover timer (e.g., T304) can be delayed until the new timer expires. The value of the new timer can be determined by the source network node and notified to the UE, or determined by the UE and notified to the source network node. Alternatively, the value of the new timer can be jointly determined on the base station side and the UE side based on a predetermined table (e.g., defined in 3GPP standards) (e.g., the base station and the UE can select the same value according to the predetermined table).

[0036] Figure 3 A scenario 300 for an enhanced handover procedure for a non-terrestrial network (NTN) according to an embodiment of this disclosure is illustrated exemplarily. In 301, a Mini-Aperture Terminal User Equipment (MAU) can receive a handover command (e.g., an RRCReconfiguration message) from a source network node (denoted as SAT#1 and / or gNB#1). In 302, upon receiving the handover command, the MAU starts a redirection timer (denoted as T) with an offset value. re-steeringIn one example, the offset value can be included in the handover command. In another example, if the handover command does not include an offset value, the Minimum Aperture Terminal Equipment (VATA) can set the offset value to the reported value of the VAT antenna reorientation duration. At 303, the VATTA can reorient its VAT antenna to the target satellite (denoted as SAT#2). At 304, after reorienting its VAT antenna to the target satellite, the VATTA can perform downlink (DL) synchronization with the target satellite. At 305, after the reorientation time expires, the VATTA can start a handover timer (denoted as T304). At 306, the VATTA can execute the handover procedure (e.g., including a random access procedure). Simultaneously, on the source satellite side, PRACH resources (e.g., random access preamble) can be reserved for the handover of the user equipment based on the offset value. For example, PRACH resources for user equipment handover can be reserved from time {t1+offset} to time {t1+offset+T304}.

[0037] Figure 4 Scenario 400 of a non-terrestrial network enhancement handover procedure according to another embodiment of this disclosure is illustrated. At 401, a Very Small Aperture (VSA) terminal user equipment (MSA) can receive a UECapabilityEnquiry message from a source network node (denoted as SAT#1 and / or gNB#1). At 402, the VSA can send a UECapabilityInformation message to the source network node, containing VSA capability information. At 403, the VSA can receive a handover command (e.g., an RRCReconfiguration message) from the source network node (denoted as SAT#1 and / or gNB#1), containing an extended handover timer value. At 404, upon receiving the handover command, the VSA starts a handover timer with an extended handover timer value (denoted as T304). At 405, the VSA can redirect its VSA terminal antenna to a target satellite (denoted as SAT#2). In section 406, after the very small aperture terminal user equipment (VSA) antenna is reoriented to point towards the target satellite, it can perform downlink synchronization with the target satellite. In section 407, the VSA can perform a handover procedure (e.g., including a random access procedure). It is noteworthy that the handover timer value is extended to cover the reorientation time of the user equipment, ensuring that the VSA has sufficient time to complete the handover procedure after the antenna reorientation operation.

[0038] Figure 5Scenario 500 illustrates a handover procedure for non-terrestrial network enhancement according to another embodiment of this disclosure. In 501, a Very Small Aperture End User Equipment (MSU) can receive a handover command (e.g., an RRCReconfiguration message) from a source network node (denoted as SAT#1 and / or gNB#1). Specifically, the handover command includes ephemeris information, epoch time, and the service start time (denoted as T1) of the target satellite. The source network node can send the handover command with an offset (denoted as a1, which may be greater than the maximum redirection time of the MSU) before the service start time. For example, the source network node can send the handover command at time {T1-a1}. In 502, after receiving the handover command, the MSU can continue data transmission and reception with the source satellite for a period of time (depending on the user equipment capabilities). In 503, the MSU can send a service stop indication to notify the network that service has ceased at the source satellite. A service stop indication (e.g., via a radio resource control (RRC) message or a medium access control (MAC) control element (CE)) can be sent based on the required redirection time (denoted as a2). For example, a Very Small Aperture End User Equipment (VSA) can send a service stop indication at time {T1-a2}. At 504, the VSA can redirect its VSA antenna to the target satellite (denoted as SAT#2). At 505, the VSA can start a handover timer at T1 (denoted as T304). At 506, the VSA can perform a handover procedure (e.g., including a random access procedure).

[0039] Figure 6 Scenario 600, an embodiment of another implementation of this disclosure, illustrates a handover procedure for enhancing non-terrestrial networks. Scenario 600 is similar to Scenario 500, except that in 601, the handover command is a conditional handover command, which includes not only the service start time of the target satellite (denoted as T1) but also the duration of the service time (denoted as D1). For example, the condition for triggering the handover procedure can be that time T1 has arrived. That is, at time T1, a very small aperture terminal user equipment can start a handover timer at D1 and then execute the handover procedure.

[0040] Exemplary Implementation

[0041] Figure 7An example communication system 700 according to an embodiment of this disclosure is illustrated, including an example communication device 710 and an example network device 720. The communication device 710 and the network device 720 can perform various functions to implement the schemes, techniques, processes, and methods described herein for enhancing handover of wireless communications in non-terrestrial networks, including the scenarios / schemes described above and processes 800 and 900 described below.

[0042] The communication device 710 may be part of an electronic device, which may be a very small aperture end-user device, such as a wireless communication device or a computing device, and may be mounted on a ship or vehicle, or on the roof of a building (e.g., a home or office) to provide internet access via satellite communication. Alternatively, the communication device 710 may be implemented as one or more integrated circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction-set computing (RISC) processors, or one or more complex-instruction-set computing (CISC) processors. The communication device 710 may include... Figure 7 The communication device 710 may include at least some of the components shown, such as processor 712. It may also include one or more other components unrelated to the proposed solutions of this disclosure (e.g., internal power supply, display device, and / or user interface device), and therefore, these components of the communication device 710 are... Figure 7 This is not shown in the text or described below, in order to simplify and refine the content.

[0043] Network device 720 may be part of an electronic device, which may be a network node, such as a satellite, base station, microcell, router, or gateway for a non-terrestrial network (NTN). For example, network device 720 may be implemented in an eNB / gNB / TRP in a satellite and / or 4G / 5G, NR, Internet of Things (IoT), Narrowband Internet of Things (NB-IoT), or Industrial Internet of Things (IIoT) network. Alternatively, network device 720 may be implemented as one or more integrated circuit chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, or one or more Reduced Instruction Set Computer (RISC) or Complex Instruction Set Computer (CISC) processors. Network device 720 may include... Figure 7The network device 720 may include at least some of the components shown, such as processor 722. It may also include one or more other components unrelated to the scheme presented in this disclosure (e.g., internal power supply, display device, and / or user interface device); therefore, for the sake of brevity, Figure 7 The components of these network devices 720 are not shown in the document, nor are they described below.

[0044] In one aspect, each of processor 712 and processor 722 may be implemented as one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, although the singular term "processor" is used herein to refer to processor 712 and processor 722, each of processor 712 and processor 722 may include multiple processors in some implementations of this disclosure, and may include a single processor in other implementations. In another aspect, each of processor 712 and processor 722 may be implemented in hardware (and optionally firmware) comprising, for example, but not limited to, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and / or one or more transformers, these electronic components being configured and arranged to achieve the specific purposes of this disclosure. In other words, in at least some implementations, each of processor 712 and processor 722 is a dedicated machine specifically designed, arranged, and configured to perform specific tasks in devices (e.g., represented by communication device 710) and network nodes (e.g., represented by network device 720), including handover enhancements for NTNs, according to various implementations of this disclosure.

[0045] In some implementations, the communication device 710 may further include a transceiver 716 coupled to the processor 712, capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 716 may be capable of wireless communication with wireless networks of different types of user equipment (UE) and / or different radio access technologies (RATs). In some implementations, the transceiver 716 may be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, the transceiver 716 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input multiple-output (MIMO) wireless communication. In some implementations, if a mechanically directional antenna is used, the transceiver 716 may be equipped with a rotor. Alternatively, if an electronically directional antenna is used, the transceiver 716 may be equipped with a phase antenna. In some implementations, the network device 720 may further include a transceiver 726 coupled to the processor 722. The transceiver 726 may include a transceiver capable of wirelessly transmitting and receiving data. In some implementations, transceiver 726 can wirelessly communicate with different types of UEs from different RATs. In some implementations, transceiver 726 can be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, transceiver 726 can be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

[0046] In some implementations, the communication device 710 may further include a memory 714 coupled to the processor 712, which can be accessed and used to store data. In some implementations, the network device 720 may further include a memory 724 coupled to the processor 722, which can be accessed and used to store data. Both memory 714 and memory 724 may include a random-access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), thyristor RAM (T-RAM), and / or zero-capacitor RAM (Z-RAM). Alternatively, or additionally, each of memory 714 and memory 724 may include a read-only memory (ROM), such as a mask ROM, a programmable ROM (PROM), an erasable programmable ROM (EPROM), and / or an electrically erasable programmable ROM (EEPROM). Alternatively, or additionally, each of memory 714 and memory 724 may include a non-volatile random-access memory (NVRAM), such as flash memory, solid-state memory, ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), and / or phase-change memory.

[0047] Both communication device 710 and network device 720 can be communication entities capable of communicating using various proposed schemes of this disclosure. For illustrative purposes and without limitation, the capabilities of communication device 710 as a UE and network device 720 as a network node (e.g., a satellite) are described below in conjunction with procedures 800 and 900.

[0048] Explanatory process

[0049] Figure 8Example flow 800 is shown under the implementation of this disclosure. Flow 800 can be an example implementation of the above scenario / solution, whether partial or complete, for handover enhancement of NTN in wireless communication. Flow 800 can represent one aspect of the functional implementation of communication device 710. Flow 800 can include one or more operations, actions, or functions, as shown in flow blocks 810 to 840. Although shown as discrete flow blocks, the flow blocks of flow 800 can be divided into more flow blocks, merged into fewer flow blocks, or omitted according to the desired implementation. Furthermore, the flow blocks of flow 800 can be arranged according to... Figure 8 The process can be executed in the order shown, or in a different order. Process 800 can be implemented by communication device 710 or any suitable UE. For illustrative purposes only and without limitation, process 800 is described below in the context of communication device 710. Process 800 may begin with process block 810.

[0050] In process block 810, process 800 may involve the processor 712 of communication device 710 reporting very small aperture end-user equipment capability information to a first network node (e.g., network device 720) via transceiver 716, wherein the first network node includes or is associated with a first satellite. Process 800 can proceed from process block 810 to process block 820.

[0051] In process block 820, process 800 may involve processor 712 receiving a handover command from a first network node via transceiver 716, wherein the handover command indicates a handover from the first network node to a second network node that includes or is associated with a second satellite. Process 800 may proceed from process block 820 to process block 830.

[0052] In process block 830, process 800 may involve processor 712 reorienting the very small aperture terminal antenna to the second satellite during the very small aperture terminal antenna reorientation duration. Process 800 can proceed from process block 830 to process block 840.

[0053] In process block 840, process 800 may involve processor 712 performing a switch via transceiver 716 after the reorientation duration of the very small aperture terminal antenna.

[0054] In some implementations, the very small aperture terminal user equipment (MSU) capability information may include at least one of the following: (i) the type of the MSU antenna, indicating whether the MSU uses an electronic or mechanical directional antenna; (ii) the ability to receive signals from multiple satellites simultaneously; and (iii) the ability to maintain a link with the first satellite during the MSU antenna reorientation period.

[0055] In some implementations, the minimum aperture terminal user equipment capability information may include parameters related to the minimum aperture terminal antenna reorientation duration, and the parameters may indicate at least one of the following: (i) rotor speed; (ii) the numerical value of the minimum aperture terminal antenna reorientation duration; (iii) the minimum aperture terminal antenna reorientation time level; (iv) the minimum minimum aperture terminal antenna reorientation time; and (v) the maximum minimum aperture terminal antenna reorientation time.

[0056] In some implementations, process 800 may also involve the processor 712 starting a redirection timer with a value equal to the redirection duration of the very small aperture terminal antenna when it receives a handover command, and starting a handover timer when the redirection timer expires and the handover begins.

[0057] In some implementations, the switching command may include a value for the duration of the reorientation of the very small aperture terminal antenna.

[0058] In some implementations, process 800 may also involve processor 712 receiving auxiliary information from a first network node via transceiver 716, wherein the auxiliary information includes ephemeris information, epoch time, and the service start time of a second satellite. Furthermore, process 800 may also involve processor 712 determining a value for the reorientation duration of the very small aperture terminal antenna based on the auxiliary information.

[0059] In some implementations, auxiliary information may be received in a request message, and the value of the reorientation duration of the very small aperture terminal antenna may be reported to the first network node in response to the request message.

[0060] In some implementations, process 800 may also involve processor 712 starting a switching timer when a switching command is received, wherein the value configured for the switching timer is greater than the value of the reorientation duration of the very small aperture terminal antenna.

[0061] In some implementations, the handover command may include ephemeris information, epoch time, and the service start time of the second satellite. Furthermore, process 800 may also involve the processor 712 sending a service stop instruction to the first satellite via transceiver 716 before performing the handover, based on the very small aperture terminal antenna reorientation duration and the service start time.

[0062] In some implementations, the service stop indication may be sent in a Radio Resource Control (RRC) message or a Media Access Control (MAC) control unit (CE).

[0063] Figure 9A process 900 according to an embodiment of this disclosure is illustrated by way of example. Process 900 can serve as an exemplary implementation of the above-described scenario / solution, whether partially or entirely, for handover enhancements in non-terrestrial networks (NTNs) in wireless communications. Process 900 may represent one aspect of an embodiment of the features of network device 720. Process 900 may include one or more operations, actions, or functions, as shown by one or more process blocks 910 and 920. Although shown in the form of discrete process blocks, the individual process blocks of process 900 may be divided into more process blocks, merged into fewer process blocks, or omitted, depending on the desired implementation. Furthermore, the process blocks of process 900 may be arranged according to... Figure 9 The process can be executed in the order shown, or in a different order. Process 900 can be implemented by network device 720 and any variant thereof. For illustrative purposes only and without limitation, process 900 is described below in the context of network device 720. Process 900 may begin at process block 910.

[0064] In process block 910, process 900 may involve the processor 722 of network device 720 receiving very small aperture end-user equipment capability information from a device (e.g., communication device 710) via transceiver 726, wherein network device 720 includes or is associated with a first satellite. Process 900 may proceed from process block 910 to process block 920.

[0065] In process block 920, process 900 may involve processor 722 sending a handover command to device via transceiver 726 based on very small aperture end user equipment capability information, wherein the handover command indicates a switch from network device 720 to another network node including or associated with a second satellite.

[0066] In some implementations, the very small aperture terminal user equipment (MSAP) capability information may include at least one of the following: (i) the type of the MAP antenna, indicating whether the MAP uses an electronic or mechanical directional antenna; (ii) the ability to receive signals from multiple satellites simultaneously; and (iii) the ability to maintain a link with a first satellite during the MAP antenna reorientation period.

[0067] In some implementations, the minimum aperture terminal user equipment capability information may include parameters related to the minimum aperture terminal antenna reorientation duration, and the parameters may indicate at least one of the following: (i) rotor speed; (ii) the numerical value of the minimum aperture terminal antenna reorientation duration; (iii) the minimum aperture terminal antenna reorientation time level; (iv) the minimum minimum aperture terminal antenna reorientation time; and (v) the maximum minimum aperture terminal antenna reorientation time.

[0068] In some implementations, the very small aperture terminal antenna reorientation duration allows the device to reorient the very small aperture terminal antenna to a second satellite before performing a handover.

[0069] In some implementations, the switching command may include a value for the duration of the reorientation of the very small aperture terminal antenna.

[0070] In some implementations, process 900 may also involve processor 722 sending auxiliary information to device via transceiver 726, wherein the auxiliary information includes ephemeris information, epoch time, and service start time of a second satellite, so that device determines a value for the reorientation duration of the very small aperture terminal antenna based on the auxiliary information.

[0071] In some implementations, auxiliary information may be sent in a request message, and the value of the reorientation duration of the very small aperture terminal antenna may be received from the device in response to the request message.

[0072] In some implementations, the switching command may include a switching timer configured with a value greater than the reorientation duration of the very small aperture terminal antenna.

[0073] In some implementations, the switching command may include ephemeris information, epoch time, and the service start time of the second satellite. Furthermore, process 900 may also involve processor 722 receiving a service stop instruction for the first satellite via transceiver 726, wherein the service stop instruction is transmitted by the device based on the very small aperture terminal antenna redirection duration and the service start time.

[0074] In some implementations, the service stop indication may be received in a radio resource control message or a media access control unit.

[0075] Additional Notes

[0076] The topics described herein sometimes illustrate that different components are contained within or connected to different other components. It should be understood that such architectures are merely examples, and many other architectures can actually be implemented to achieve the same functionality. Conceptually, any arrangement of components to achieve the same functionality is effectively “associated” to achieve the desired function. Therefore, any two components combined in this document to achieve a specific function can be considered “associated” to achieve the desired function, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “operationally connected” or “operationally coupled” to achieve the desired function, and any two components that can be suchly associated can also be considered “operationally coupled” to achieve the desired function. Specific examples of operational coupling include, but are not limited to, physically matable and / or physically interactive components and / or wirelessly interactive and / or logically interactive components.

[0077] Furthermore, regarding the use of almost all plural and / or singular terms in this document, those skilled in the art can appropriately convert from plural to singular and / or from singular to plural depending on the context and / or application. For clarity, various singular / plural permutations are explicitly listed herein.

[0078] Furthermore, those skilled in the art will understand that terms commonly used herein, particularly in appended claims, such as the body portion of appended claims, are generally considered "open" terms. For example, the word "comprising" should be interpreted as "comprising but not limited to," the word "having" should be interpreted as "having at least," the word "including" should be interpreted as "including but not limited to," and so on. Those skilled in the art will also further understand that if a particular quantity is introduced in a claim intentionally, that intention will be explicitly stated in the claim; if no such statement is made, then such intention does not exist. For example, for ease of understanding, appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce the content of the claim. However, the use of such phrases should not be interpreted as meaning that any claim containing such content is limited to containing only one instance of that content when the content of the claim is introduced by the indefinite article "a" or "one," even if the same claim contains the introductory phrase "one or more" or "at least one" and indefinite articles such as "a" or "one," for example, "a" and / or "one" should be interpreted as "at least one" or "one or more"; the same applies to definite articles used to introduce the content of the claim. Furthermore, even if a specific quantity is explicitly stated in the claims, those skilled in the art will recognize that such a statement should be interpreted as at least the stated quantity. For example, stating "two items" alone, without further modification, means at least two items, or two or more items. Additionally, when using conventions such as "at least one of the following: A, B, and C," such structures should generally be interpreted in the way that those skilled in the art understand the convention. For example, "a system having at least one of the following: A, B, and C" includes, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and systems having both A, B, and C. Similarly, when using conventions such as "at least one of the following: A, B, or C," such structures should generally be interpreted in the way that those skilled in the art understand the convention. For example, "a system having at least one of the following: A, B, or C" includes, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and systems having both A, B, and C. Those skilled in the art will further understand that virtually any disjunctive words and / or phrases appearing in the description, claims, or drawings, when presenting two or more alternative terms, should be understood to include the possibility of including one of the terms, either term, or both terms. For example, the phrase "A or B" should be understood to include the possibility of including "A," or "B," or "A and B."

[0079] As can be seen from the foregoing, various embodiments of this disclosure have been described herein for illustrative purposes, and various modifications can be made without departing from the scope and spirit of this disclosure. Therefore, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are determined by the claims.

Claims

1. A method, comprising: A processor of a device reports very small aperture end-user equipment capability information to a first network node, wherein the first network node includes or is associated with a first satellite; The processor receives a handover command from the first network node, wherein the handover command indicates a handover from the first network node to a second network node, the second network node including or associated with a second satellite; The processor redirects a very small aperture terminal antenna to the second satellite during the redirection period of the very small aperture terminal antenna; and The processor performs the switch after the reorientation period of the very small aperture terminal antenna.

2. The method of claim 1, wherein the extremely small aperture terminal user equipment capability information includes at least one of the following: A very small aperture terminal antenna type indicates whether a very small aperture terminal user equipment uses an electronic directional antenna or a mechanical directional antenna; The ability to receive signals from multiple satellites simultaneously; and The ability to maintain a link with the first satellite during the reorientation period of the extremely small aperture terminal antenna.

3. The method of claim 1, wherein the very small aperture terminal user equipment capability information includes a parameter related to the very small aperture terminal antenna reorientation duration, and the parameter indicates at least one of the following: Rotor speed; A value for the reorientation duration of the extremely small aperture terminal antenna; Reorientation time level of a very small aperture terminal antenna; Reorientation time of a minimum aperture terminal antenna; and Reorientation time of a maximum-minimum-diameter terminal antenna.

4. The method of claim 1, further comprising: When the processor receives the switching command, it starts a reorientation timer with a value for the reorientation duration of the very small aperture terminal antenna; as well as The processor starts a switching timer when the redirection timer expires and the switching begins.

5. The method of claim 4, wherein the switching command includes the value of the reorientation duration of the minimal aperture terminal antenna.

6. The method of claim 1, further comprising: The processor receives auxiliary information from the first network node, wherein the auxiliary information includes ephemeris information, an epoch time, and a service start time of the second satellite; as well as The processor determines a value for the reorientation duration of the extremely small aperture terminal antenna based on this auxiliary information.

7. The method of claim 6, wherein the auxiliary information is received in a request message, and the value of the reorientation duration of the minimal aperture terminal antenna is reported to the first network node in response to the request message.

8. The method of claim 1, further comprising: When the processor receives the switching command, it starts a switching timer, wherein a value configured for the switching timer is greater than the value of the reorientation duration of the very small aperture terminal antenna.

9. The method of claim 1, wherein the switching command includes ephemeris information, an epoch time, and a service start time of the second satellite, and the method further includes: Before performing the switch, the processor sends a service stop instruction to the first satellite based on the reorientation duration of the very small aperture terminal antenna and the service start time.

10. The method of claim 9, wherein the service stop instruction is sent in a radio resource control message or a media access control unit.

11. A method comprising: A processor of a first network node receives very small aperture terminal user equipment capability information from a device, wherein the first network node includes or is associated with a first satellite; as well as The processor sends a handover command to the device based on the capability information of the very small aperture terminal user equipment, wherein the handover command indicates a switch from the first network node to a second network node, the second network node including or associated with a second satellite.

12. The method of claim 11, wherein the extremely small aperture terminal user equipment capability information includes at least one of the following: A very small aperture terminal antenna type indicates whether a very small aperture terminal user equipment uses an electronic directional antenna or a mechanical directional antenna; The ability to receive signals from multiple satellites simultaneously; and The ability to maintain a link with the first satellite during the reorientation period of the extremely small aperture terminal antenna.

13. The method of claim 11, wherein the very small aperture terminal user equipment capability information includes a parameter related to the very small aperture terminal antenna reorientation duration, and the parameter indicates at least one of the following: Rotor speed; A value for the reorientation duration of the extremely small aperture terminal antenna; Reorientation time level of a very small aperture terminal antenna; Reorientation time of a minimum aperture terminal antenna; and Reorientation time of a maximum-minimum-diameter terminal antenna.

14. The method of claim 11, wherein the minimum aperture terminal antenna reorientation duration allows the device to reorient a minimum aperture terminal antenna to the second satellite prior to performing the switch.

15. The method of claim 11, wherein the switching command includes a value for the reorientation duration of the very small aperture terminal antenna.

16. The method of claim 11, further comprising: The processor sends auxiliary information to the device, including ephemeris information, an epoch time, and the service start time of the second satellite, so that the device can determine a value for the reorientation duration of the very small aperture terminal antenna based on the auxiliary information.

17. The method of claim 16, wherein the auxiliary information is sent in a request message, and the value of the reorientation duration of the minimal aperture terminal antenna is received from the device in response to the request message.

18. The method of claim 11, wherein the switching command includes a switching timer configured with a value greater than the value of the reorientation duration of the very small aperture terminal antenna.

19. The method of claim 11, wherein the switching command includes ephemeris information, an epoch time, and a service start time of the second satellite, and the method further includes: The processor receives a service stop instruction for the first satellite, wherein the service stop instruction is sent by the device based on the reorientation duration of the very small aperture terminal antenna and the service start time.

20. The method of claim 19, wherein the service stop instruction is received in a radio resource control message or a media access control unit.

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