Timing advance reporting

Abstract

The embodiment of the invention relates to a method, equipment and device for timing advance reporting and a computer readable storage medium. In one method, a first apparatus determines a predicted timing advance associated with a target non-terrestrial network device prior to transitioning a connection from a source non-terrestrial network device to the target non-terrestrial network device. A source non-terrestrial network device serves a first apparatus. The target non-terrestrial network device provides a service to the first apparatus after the transition. Prior to the transition, the first device transmits information regarding the predicted timing advance to the second device.

Description

Technical Field

[0001] Various example embodiments of the present disclosure relate generally to the field of telecommunications, and in particular to methods, devices, apparatuses, and computer-readable storage media for timing advance (TA) reporting. Background Art

[0002] Non-terrestrial communications can be complementary to terrestrial deployments, where satellite connectivity can provide coverage beyond that of terrestrial deployments. In non-terrestrial network (NTN) systems, fifth generation (5G) base stations (gNBs) or gNB functionality are deployed on satellites or relayed in a transparent manner by gNBs to provide communications coverage over very large areas that would otherwise be unreachable by cellular networks.

[0003] In NTN, cells originating from different satellites are associated with different physical cell identities (PCIs). Therefore, a fixed user equipment (UE) can experience continuous layer 3 (L3) mobility when the serving satellite moves out of coverage and a new satellite takes over the coverage of a geographical area. Unchanged PCI after satellite switching has been proposed with the aim of reducing signaling overhead and simplifying the radio resource control (RRC) procedure for the UE. Summary of the invention

[0004] In a first aspect of the present disclosure, a first device is provided. The first device includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, causes the first device to: determine a predicted timing advance associated with a target non-terrestrial network device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source terrestrial device serving the first device, and after the switching, the target non-terrestrial network device serving the first device; and transmit information about the predicted timing advance to a second device before the switching.

[0005] In a second aspect of the present disclosure, a second device is provided. The second device includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, causes the second device to: receive information about a predicted timing advance associated with a target non-terrestrial network device from a first device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after the switching, the target non-terrestrial network device serving the first device; and determine a configuration of a transmission time offset for transmissions of the first device based on the information.

[0006] In a third aspect of the present disclosure, a method is provided. The method includes: determining, at a first device, a predicted timing advance associated with a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after a switch, the target non-terrestrial network device serving the first device; and transmitting information about the predicted timing advance to a second device before the switch.

[0007] In a fourth aspect of the present disclosure, a method is provided. The method includes: receiving, at a second device, information about a predicted timing advance associated with a target non-terrestrial network device from a first device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after the switching, the target non-terrestrial network device switching to serve the first device; and determining a configuration of a transmission time offset for transmissions of the first device based on the information.

[0008] In a fifth aspect of the present disclosure, a first device is provided. The first device includes: a component for determining a predicted timing advance associated with a target non-terrestrial network device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after the switching, the target non-terrestrial network device serving the first device; and a component for transmitting information about the predicted timing advance to a second device before the switching.

[0009] In a sixth aspect of the present disclosure, a second device is provided. The second device includes a component for receiving information about a predicted timing advance associated with a target non-terrestrial network device from a first device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after the switching, the target non-terrestrial network device switches to serve the first device; and a component for determining a configuration of a transmission time offset for transmissions of the first device based on the information.

[0010] In a seventh aspect of the present disclosure, a computer-readable medium is provided, wherein the computer-readable medium includes instructions stored thereon, and the instructions are used to cause a device to at least execute the method according to the third aspect or the fourth aspect.

[0011] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0013] Figure 1AAn example communication environment is shown in which example embodiments of the present disclosure may be implemented;

[0014] Figure 1B Another example communication environment in which example embodiments of the present disclosure may be implemented is shown;

[0015] Figure 2 shows a signaling diagram for timing advance reporting according to some example embodiments of the present disclosure;

[0016] Figure 3 shows an example diagram illustrating time points for transmission according to some example embodiments of the present disclosure;

[0017] Figure 4A and Figure 4B An example medium access control element (MAC CE) format for timing advance reporting according to some example embodiments of the present disclosure is respectively shown;

[0018] Figure 5 An example diagram showing scheduling time relationships according to some example embodiments of the present disclosure;

[0019] Figure 6 A flowchart showing a method implemented at a first device according to some example embodiments of the present disclosure is shown;

[0020] Figure 7 A flowchart showing a method implemented at a second device according to some example embodiments of the present disclosure is shown;

[0021] Figure 8 shows a simplified block diagram of a device suitable for implementing an example embodiment of the present disclosure; and

[0022] Fig. 9 A block diagram of an example computer-readable medium is shown according to some example embodiments of the present disclosure.

[0023] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0024] The principle of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described only to illustrate and help those skilled in the art to understand and implement the present disclosure, and do not imply any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways except the way described below.

[0025] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0026] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered within the knowledge of those skilled in the art that other embodiments may be combined to affect such feature, structure, or characteristic, whether or not explicitly described.

[0027] It should be understood that although the terms "first", "second", etc. may be used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0028] As used herein, “at least one of: ” and “at least one of ” and similar expressions, where a list of two or more elements is combined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0029] As used herein, unless explicitly stated, performing a step "in response to A" does not indicate that the step is performed immediately after "A" occurs, and may include one or more intermediate steps.

[0030] The terms used herein are used only to describe specific embodiments and are not intended to limit the example embodiments. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprise", "including", "having", "having", "including" and / or "comprising", when used herein, specify the presence of the features, elements and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0031] The term "circuitry" as used in this application may refer to one or more or all of the following:

[0032] (a) hardware circuit implementation only (such as implementation in analog and / or digital circuits only) and

[0033] (b) a combination of hardware circuitry and software such as (where applicable):

[0034] (i) a combination of analog and / or digital hardware circuits and software / firmware and

[0035] (ii) any portion of a hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions) and

[0036] (c) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), that require software (e.g., firmware) to operate, but which may not be present when the software is not required to operate.

[0037] The definition of circuitry applies to all uses of the term in this application, including any claims. As yet another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example (and if applicable to a particular claim element), a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0038] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocol and / or any other protocol currently known or developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there will certainly be future types of communication technologies and systems that can implement the present disclosure. The scope of the present disclosure should not be limited to the above-mentioned system.

[0039] As used herein, the term "network device" or "network access device" refers to a node in a communication network, via which a terminal device accesses the network and receives services from it. A network device may refer to a base station (BS) or an access point (AP), such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a NR NB (also referred to as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an integrated access and backhaul (IAB) node, a low-power node (such as a femto, a micro, a non-terrestrial network (NTN)) or a non-terrestrial network device (such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous orbit (GEO) satellite, an aircraft network device), etc., depending on the terminology and technology applied. In some example embodiments, a radio access network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) located at an IAB donor node. The IAB node includes a mobile terminal (IAB-MT) part, which behaves like a UE towards a parent node, and the DU part of the IAB node behaves like a base station towards a next-hop IAB node.

[0040] The term "terminal device" refers to any terminal device that may be capable of wireless communication. As an example and not limitation, a terminal device may also be referred to as a communication device, a user equipment (UE), a user station (SS), a portable user station, a mobile station (MS), or an access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless regional loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device (such as a digital camera), a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop device (LME), a USB dongle, a smart device, a wireless client device (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. The terminal device may also correspond to the mobile terminal (MT) part of an IAB node (eg, a relay node).In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0041] As used herein, the term "resource", "transmission resource", "resource block", "physical resource block" (PRB), "uplink resource" or "downlink resource" may refer to any resource used to perform communication, for example, communication between a terminal device and a network device, such as time domain resources, frequency domain resources, spatial domain resources, code domain resources, or any other resource capable of communication. In the following, unless explicitly stated, resources in both the frequency domain and the time domain will be used as examples of transmission resources to describe some example embodiments of the present disclosure. Note that the example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0042] As briefly mentioned, in NTN systems, 5G base stations (gNBs) or gNB functions are deployed on satellites or relayed by gNBs in a transparent manner to provide communication coverage over very large areas. In some mechanisms, enhancements for both NTN-NTN and NTN-terrestrial network (TN) mobility and service continuity are proposed. For example, methods for further enhancement from New Radio (NR) TN to NR NTN as a baseline may include specifying NTN-NTN handover enhancements for RRC_CONNECTED UEs in quasi-Earth fixed cells and Earth mobile cells to reduce signaling overhead.

[0043] In NTN, cells originating from different satellites are associated with different PCIs. Thus, a fixed UE may experience continuous Layer 3 (L3) mobility as the serving satellite moves out of coverage and a new satellite takes over coverage of a geographical area.

[0044] In some mechanisms, after the target satellite starts providing coverage, the UE can obtain downlink (DL) synchronization by reading the synchronization signal block (SSB) provided by the target satellite. For UL synchronization, the most direct way is to perform a random access channel (RACH) to obtain uplink (UL) synchronization. Obviously, contention-based random access (CBRA) can be an option to obtain UL synchronization. Non-contention random access (CFRA) that requires dedicated RACH resources for the UE before the satellite switch occurs can also be supported.

[0045] RACH-free handover in inter-satellite handover with the same gateway / gNB is supported. The unchanged PCI scenario without handover is similar to the scenario of RACH-free inter-satellite handover with the same gateway / gNB. That is, for the unchanged PCI scenario, RACH-free can also be supported. This means that after the inter-satellite handover without RACH, the UE can have a valid TA of the target cell. The question of how to obtain the TA of the target cell may require further discussion.

[0046] After satellite switching and UE resynchronization to the serving cell (via the target satellite), the NW will continue to schedule the UE for UL transmission with pre-allocated resources or dynamically granted resources.

[0047] In some mechanisms, a constant PCI has been proposed for the purpose of reducing signaling overhead and simplifying the radio resource control (RRC) procedure for the UE. In a constant PCI scenario without handover, UE acquisition of UL synchronization without RACH may be supported.

[0048] In some mechanisms, CBRA / CFRA procedures may be used for UE to reacquire UL synchronization with the target satellite in a PCI unchanged scenario without handover. NTN RACH-less handover (HO) may be supported for intra-satellite handover with the same feeder feeder link. That is, with the same gateway / gNB. NTN RACH-less HO may be supported for inter-satellite handover with different feeder links, that is, handover with gateway / gNB, inter-satellite handover with gateway / gNB handover, and inter-satellite handover with the same gateway / gNB.

[0049] Some protocols related to the solution of unchanged PCI are discussed. In the case of quasi-geo-fixed cells, satellite transition without PCI change (no L3 mobility required) is supported for hard satellite transition with the same synchronization signal block (SSB) frequency and the same gNB (no security key change).

[0050] In the 3rd Generation Partnership Project (3GPP) Rel-18, the focus is on transparent architecture, and the most obvious case is when the cells are provided by the same gNB, that is, the same cell with fixed PCI is provided by the same gNB. In this case, only the satellite node is changed. However, in theory, this can also work with different gNBs and potentially even for regeneration scenarios.

[0051] In some mechanisms, how to perform synchronization with the serving cell after satellite switching is proposed. For example, it is proposed to support UE to obtain UL synchronization without random access channel (RACH) in unchanged PCI (no handover) scenario (after satellite switching to serving cell).

[0052] In the unchanged PCI scenario, the satellite will be switched without L3 mobility procedures (e.g., handover). When the RACH-free procedure is combined with the PCI unchanged solution, the UE can synchronize to the target satellite without RACH. After the switch, the NW continues to schedule the UE dynamically or via pre-allocated resources. In the hard switch unchanged PCI scenario (i.e., no handover), the UE needs to know when the UE attempts to resynchronize.

[0053] However, when a satellite switch occurs, the UE may experience a TA hopping problem. When TA hopping occurs after a satellite switch, if the network (NW) is not aware of the new TA targeting the new satellite, the physical uplink shared channel (PUSCH) transmission to the target satellite may fail. The reason is that in order to guarantee UL transmission, the Koffset configured by the NW should satisfy Koffset>TA+UL processing delay–4, which may not be satisfied when a TA hopping occurs. For example, when the TA increases by 10ms after the switch and the NW does not adjust the Koffset accordingly due to the lack of new TA information, the UE cannot perform UL transmission due to the outdated Koffset.

[0054] Furthermore, if the NW knows the time of satellite switching and uses the maximum UE-eNB RTT among all UEs, the scheduling delay will be increased.

[0055] In order to solve at least part of the above problems or other potential problems, a solution for timing advance (TA) reporting is proposed. According to an example embodiment, a first device (such as a terminal device) determines a predicted timing advance associated with a target non-terrestrial network device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device. The source non-terrestrial network device serves the first device. The target non-terrestrial network device provides services to the first device after switching. Before the satellite switches, the first device transmits information about the predicted timing advance to a second device (such as a network device).

[0056] In this way, the second device can learn the new predicted TA. Using the new predicted TA, the second device can continue scheduling in the serving cell after the switch.

[0057] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0058] Figure 1A An example communication environment 100 in which example embodiments of the present disclosure may be implemented is shown. In the communication environment 100, a first device 110 and a second device 120 may communicate with each other through a non-terrestrial network (NTN) device 130. In some example embodiments, the NTN device 130 may be a satellite or a high altitude platform station (HAPS). The second device 120 may communicate with a data network 140.

[0059] In the following, for the purpose of illustration, some example embodiments are described with the first device 110 operating as a terminal device and the second device 120 operating as a network device. However, in some example embodiments, the operations described in conjunction with the terminal device may be implemented at a network device or other device, and the operations described in conjunction with the network device may be implemented at a terminal device or other device.

[0060] In some example embodiments, if the second device 120 is a network device, it may be a gNB connected to the NTN device 130 (in a transparent architecture) or a gNB located in the NTN device 130 (in a regenerative architecture).

[0061] In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, the link 134 between the second device 120 and the NTN device 130 may be referred to as a feeding link, and the link 132 between the NTN device 130 and the first device 110 may be referred to as a service link.

[0062] In some example embodiments, the first device 110 is located within a service area or coverage area of ​​the NTN equipment 130. For example, the first device 110 may be located in a different beam footprint.

[0063] In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, the link from the second device 120 to the first device 110 is referred to as a downlink (DL), and the link from the first device 110 to the second device 120 is referred to as an uplink (UL). In the DL, the second device 120 is a transmitting (TX) device (or transmitter), and the first device 110 is a receiving (RX) device (or receiver). In the UL, the first device 110 is a TX device (or transmitter), and the second device 120 is an RX device (or receiver).

[0064] It should be understood that Figure 1A The number of devices and their connections shown in FIG. 1 are for illustration purposes only and do not suggest any limitation. Communication environment 100 may include any suitable number of devices configured to implement example embodiments of the present disclosure.

[0065] The communication in the communication environment 100 can be implemented according to any appropriate communication protocol, including but not limited to cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), etc., wireless local area network communication protocols such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or developed in the future. In addition, the communication can utilize any appropriate wireless communication technology, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiple access (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM) and / or any other technology currently known or developed in the future.

[0066] In some example embodiments, NTN equipment switchover, such as satellite switchover, may occur in some circumstances. Figure 1B Another example communication environment 150 is shown in which example embodiments of the present disclosure may be implemented. In the communication environment 150, NTN equipment conversion may occur.

[0067] In the following description, it may be assumed that the first device 110 is stationary or mobile and is currently served by the NTN device 130. For example, the NTN device 130 may be a serving satellite or referred to as a source satellite. As used herein, the serving NTN device 130 may also be referred to as a source NTN device 130.

[0068] When the source NTN device 130 moves away from the first device 110, for example, in the moving direction 155, and another NTN device 160 is closer to the first device, then at a point in time, an NTN device switch will occur. As used herein, the NTN device 160 may be referred to as a "target NTN device 160" that serves the first device 110 after the NTN device switch. As used herein, the term "NTN device switch" may also be referred to as a "switch."

[0069] The network (e.g., the second device 120) can indicate to the first device 110 when the transition will occur. The second device 120 instructs the first device 110 when and how to perform DL and UL resynchronization to the new cell after the transition. The first device 110 can adjust its timing and Doppler shift parameters for operation toward the new cell. The second device 120 can alternatively accept an interrupt gap for the first device 110 to detect the new timing and adapt to it. Since the PCI, second device 120, security keys, and SSB frequency remain the same, the transition can be largely transparent to the first device 110. Since the PCI, gNB, security keys, and SSB frequency remain the same, the satellite transition can be largely transparent to the first device 110. Once the target NTN equipment 160 takes over, the first device 110 can perform DL / UL synchronization operations to adjust time and frequency.

[0070] In some example embodiments, for a quasi-Earth Fixed Cell (EFC) scenario, the geographic area 170 is associated with a physical cell ID (PCI) and the second device 120. For a constant PCI scenario, the second device 120 may serve the same coverage (e.g., geographic area 170) by connecting to different NTN devices (e.g., source NTN device 130 and target NTN device 160), and the PCI may remain unchanged after the satellite switch. In this case, the NTN cell is deployed as an EFC because the coverage area of ​​the cell does not change.

[0071] When NTN equipment switching occurs, the serving NTN equipment changes from the source NTN equipment 130 to the target NTN equipment 160. The serving link 132 between the first device 110 and the source NTN equipment 130 may change to a different serving link 162 between the first device 110 and the target NTN equipment 160. Likewise, the feeding link 134 between the second device 110 and the source NTN equipment 130 may change to a different feeding link 164 between the second device 120 and the target NTN equipment 160.

[0072] like Figure 1B As shown, if the first device is served by the source NTN equipment 130, the TA of the first device 110 may be equal to the round trip time (RTT) between the first device 110 and the second device 120, which includes the propagation delay SL_1 corresponding to the service link 132 and the propagation delay FL_1 corresponding to the feeder link 134 (i.e., SL_1+FL_1). After the first device 110 is switched to the target NTN equipment 160, the new TA of the first device 110 may be equal to the round trip time (RTT) between the first device 110 and the second device 120, which includes the propagation delay SL_2 corresponding to the service link 162 and the propagation delay FL_2 corresponding to the feeder link 164 (i.e., SL_2+FL_2).

[0073] If the first device 110 is located at the near edge of the coverage of the source NTN equipment 130, after the switch, since (SL_2+FL_2) is greater than (SL_1+FL_1), the TA jump problem will occur. The value of the TA jump (also called the TA jump value) may depend on the cell coverage radius, the elevation angle of the serving satellite, and the location of the first device 110. For example, the TA jump value may be at least greater than the differential delay between the UEs served by the satellite. As an example, the TA jump value may be 10 ms in a geosynchronous equatorial orbit (GEO). It should be understood that the TA jump value may be any suitable time value.

[0074] In some example embodiments, the second device 120 may need to know the new TA of the target NTN device 160 to obtain the TA jump value. According to some example embodiments of the present disclosure, before switching the connection from the source NTN device 130 serving the first device 110 to the target NTN device 160, the first device 110 determines a predicted TA associated with the target NTN device 160. The target NTN device 160 is configured to provide service to the first device 110 after the switching. The first device 110 transmits information about the predicted timing advance to the second device 120 before the switching.

[0075] In this way, the second device 120 may be informed of the new predicted TA. Using the new predicted TA, the second device 120 may continue scheduling in the serving cell after the switch.

[0076] Figure 2 A signaling diagram 200 for TA reporting according to some example embodiments of the present disclosure is shown. The signaling diagram 200 relates to Figure 1A and Figure 1B For the purpose of illustration, reference will be made to the first device 110 and the second device 120. Figure 1A and Figure 1B A signaling diagram 200 is described.

[0077] Despite Figure 2 A single first device 110 and a single second device 120 are shown in FIG. 1 , but it should be understood that there may be multiple devices that perform similar operations as described below with respect to the first device 110 or the second device 120 .

[0078] exist Figure 2 In the example of, the second device 120 may be connected to at least one of the following: the source NTN device 130 before conversion, the target NTN device 160. Alternatively, in some example embodiments, the second device 120 may be located in at least one of the following: the source NTN device 130 before conversion, the target NTN device 160. The source NTN device 130 and / or the target NTN device 160 may be a satellite or a high-altitude platform station.

[0079] It should be noted that the exemplary embodiments of the present disclosure may be applied to any suitable scenario, for example, a RACH-free satellite handover scenario in an unchanged PCI scenario, or a RACH-free transition scenario in an NTN scenario if there is a RACH-free satellite transition. For illustrative purposes only, the exemplary embodiments of the present disclosure are described with reference to a scenario of a RACH-free satellite transition.

[0080] In operation, before switching a connection from a source NTN device, such as source NTN device 130, to a target NTN device, the first device 110 determines (230) a predicted TA associated with a target NTN device, such as target NTN device 160. The source NTN device serves the first device 110. The target NTN device is configured to provide service to the first device 110 after switching.

[0081] The first device 110 transmits (250) information about the predicted timing advance to the second device 120 before the switch. The second device 120 receives (255) the information. For example, before the satellite switch occurs, the first device 110 reports the predicted TA for the serving cell with the target satellite to the second device 120.

[0082] In some example embodiments, the first device 110 may transmit at least one of the following to the second device 120 at a first time point prior to the time window for the transition: the information, a request for transmission of the information. For example, if resources are available for transmission at the first time point, the first device 110 may transmit (250) the information at the first time point. If no resources are available for information transmission at the first time point, the first device 110 may transmit a request for transmission at the first time point. That is, the first device 110 may trigger a predicted TA report for the target NTN device 160 before the transition. For example, the request for information transmission may be a scheduling request or a random access request.

[0083] In some example embodiments, the time window may be predefined or configured. As an example, the second device 120 may transmit (240) the configuration of the time window to the first device 110. The first device 110 may receive (245) the configuration of the time window. The second device 120 may assume that the TA information transmission can be completed within the time window.

[0084] In some example embodiments, the second device 120 may determine the time window based on at least one of the following: the RTT between the first device 110 and the second device 120, the number of retransmissions, or the scheduling request (SR) period. It should be understood that these example parameters for determining the time window are only for illustrative purposes and do not imply any limitation. The second device 120 may determine the time window based on any other suitable parameters.

[0085] Figure 3 An example diagram 300 showing time points for information transmission according to some example embodiments of the present disclosure is shown. As shown, a time window 310 is configured by the second device 120. The time window 310 precedes a switch time point 330. A request for transmission of information or information about a predicted TA may be sent at a first time point 340 before a start time point 335 of the time window 310. It should be understood that in some example embodiments, the first time point 340 may be at the start time point 335 of the time window 310. In this way, the first device 110 may trigger a predicted TA report for the target NTN device 160 before the (satellite switch time - time window) point. Figure 3 Additional time points are shown, which will be used for the transmission of additional information.

[0086] Return to reference Figure 2In some example embodiments, the predicted TA information may be transmitted (250) based on one or more conditions. For example, the first device 110 may determine (235) whether a difference between a predicted TA associated with the target NTN device 160 and a reference TA associated with the source NTN device 130 is greater than or equal to a threshold. If the first device 110 determines (235) that the difference is greater than or equal to the threshold, the first device 110 may transmit (250) the information to the second device 120.

[0087] In this way, only when the change (between the reported TA for the serving cell with the source NTN device 130 and the predicted TA for the serving cell with the target NTN device 160) is greater than or equal to the threshold, the first device 110 reports the predicted TA for the serving cell with the target NTN device 160. Signaling overhead can therefore be reduced.

[0088] It should be understood that other conditions besides the threshold value may be used for the transmission of the predicted TA information.The scope of the present disclosure is not limited in this respect.

[0089] As described, the first device 110 determines (230) a predicted TA. In some example embodiments, the second device 120 may transmit (220) the ephemeris information and the TA parameter set of the target NTN device 160 to the first device 110. The first device 110 may receive (225) the ephemeris information and the TA parameter set of the target NTN device 160. As an example, the TA parameter set may be a common TA parameter. The first device 110 may determine (230) a predicted TA based on the ephemeris information and the TA parameter set.

[0090] In this way, the second device 120 provides the ephemeris information of the target NTN equipment 160, such as the ephemeris information of the target satellite and the common TA parameters, to the first device 110 before the satellite switching occurs. Therefore, it enables the first device 110 to predict the TA for the serving cell using the target satellite.

[0091] In some example embodiments, the second device 120 may transmit (220) ephemeris information and a set of TA parameters to the first device 110 at a second time point prior to a first time point for a predicted TA request or report. An offset of the second time point relative to the first time point may be predefined or configured. In another example, an offset of the second time point relative to a time window for predicted TA transmission may be predefined or configured. For example, the second device 120 may transmit (210) a configuration of the offset to the first device 110. The first device 110 may receive (215) the configuration of the offset. The offset may be relative to the first time point or a time window associated with the first time point.

[0092] like Figure 3 As shown, the offset 320 is configured by the second device 120. The offset 320 precedes the time point 335 of the time window 310. The ephemeris information and the TA parameter set may be transmitted (210) at a second time point 350 before the time point 345 having the offset 320 relative to the time window 310. It should be understood that in some example embodiments, the second time point 350 may be at the time point 345.

[0093] In this way, the second device 120 can configure the offset to the first device 110, wherein the second device 120 can provide the information and TA parameters of the target NTN device 160 at the time point of (satellite switching time-time window-offset). As an example, the ephemeris information and the TA parameter set can be provided to the first device 110 via a system information block (SIB) or any other suitable signaling. For example, in the connected mode, t-Service in SIB19 can be interpreted by the first device 110 to know that a satellite change occurs or a feeder link change occurs. The first device 110 can receive or decode the ephemeris information and the TA parameter set starting from the second time point.

[0094] In some example embodiments, the second device 120 may determine the offset value by considering a time required for TA estimation in the first device 110 based on the ephemeris and the common TA and a configured system information (SI) modification period.

[0095] In some example embodiments, a predicted TA for a serving cell having a target NTN device 160 may be reported in a different format. In one example, information about the predicted TA may include a predicted TA associated with the target NTN device 160, such as a predicted TA value. The first device 110 may report the predicted TA via an RRC message such as UE assistance information, wherein an absolute value of the predicted TA may be included. The first device 110 may alternatively report the predicted TA via a new media access control control element (MAC CE), such as a new UL MAC CE. For example, a plurality of most significant bits (MSBs) or a plurality of least significant bits (LSBs) in at least one octet (OCT) in the MAC CE may be used for the predicted TA value.

[0096] Figure 4AAn example MAC CE format 410 for TA reporting is shown. A MAC CE for predicted TA reporting may be identified by a MAC subheader with a logical channel identifier (LCID). For example, six LSB bits of the first OCT 412 in the MAC CE and eight bits in the second OCT 414 next to the first OCT 412 may be used for the predicted TA value. The two MSB bits in the first OCT 412 may be reserved. The reserved bits may be set to 0. It should be understood that the example MAC CE format 410 is for illustrative purposes only and does not imply any limitation. Any appropriate MAC CE may be applied. The scope of the present disclosure is not limited in this regard.

[0097] Alternatively or additionally, in some example embodiments, the information about the predicted TA may include a reference TA associated with the source NTN device 130 and a difference between the predicted TA and the reference TA. As used herein, the difference between the predicted TA and the reference TA may also be referred to as a "TA difference" or a "TA jump" or a "TA jump value". For example, the difference between the predicted TA and the reference TA may be carried in at least one reserved bit in the MAC CE. The at least one reserved bit may indicate a ratio of the difference to a predetermined TA difference.

[0098] Multiple bits in the MAC CE may be used to reference the TA. For example, in a frequency range 1 (FR1) scenario, the TA field indicates the minimum integer number of time slots greater than or equal to the TA value using a subcarrier spacing of 15 kHz. The length of this field may be 14 bits. That is, 14 bits may be used to reference the TA. It should be understood that in other scenarios, more or fewer bits may be used to reference the TA.

[0099] Figure 4B An example MAC CE format 430 for a predicted TA and a reference TA is shown. As shown, the two MSB bits in the first OCT 432 in the MAC CE may indicate the difference between the predicted TA and the reference TA. The six LSB bits in the OCT 432 in the MAC CE and the eight bits in the second OCT 434 next to the first OCT 432 may indicate the reference TA value. It should be understood that the example MAC CE format 430 is for illustrative purposes only and does not imply any limitation. Any appropriate MAC CE may be applied. The scope of the present disclosure is not limited in this respect.

[0100] In some example embodiments, second device 120 may indicate a predetermined TA difference value, such as a maximum TA jump, to first device 110 via RRC or SIB. Alternatively, the predetermined TA difference value or the maximum TA jump may be predefined, such as 20 ms or any suitable value.

[0101] The first device 110 may indicate the TA hopping via an index in the spare bits in the MAC CE to indicate the percentage of the maximum TA hopping. Figure 4B In the example of , two reserved bits can indicate the TA jump value. The index in the two reserved bits can be 00 / 01 / 10 / 11. For example, "00" means that the TA jump value is less than one-quarter of the maximum TA jump, "01" means that the TA jump value is in the range of one-quarter to one-half of the maximum TA jump, "10" means that the TA jump range is in the range of one-half to three-quarters of the maximum TA jump, and "11" means that the TA jump value is in the range of three-quarters to all of the maximum TA jump. Alternatively, the index "00" can be used to indicate no TA jump, while the indexes "01" / "10" / "11" can be used to indicate other TA jump ranges. It should be understood that these example indexes and TA jump ranges are for illustrative purposes only and do not imply any limitation.

[0102] The predicted TA for the serving cell with the target NTN device 160 may be equal to the sum of the TA value reported by the serving cell with the source NTN device 130 and the TA jump. Figure 4B As shown, the TA value for the source NTN device 130 may be indicated via the traditional 14 bits in the UL MAC CE, while the TA hopping may be indicated via two spare bits in the same MAC CE.

[0103] In this way, the TA for the serving cell with the source NTN device 130 and the TA for the serving cell with the target NTN device 160 are both reported to the second device 120 via a single UL MAC CE. Signaling can therefore be more efficient. By reusing the R bit in the conventional UL MAC CE as a TA report for the serving cell with the source satellite, the signaling design is efficient.

[0104] Back to Figure 2 In some example embodiments, the second device 120 determines (260) a configuration of a transmission time offset for transmissions of the first device 110 based on the information about the predicted TA. The second device 120 may transmit (265) the configuration of the transmission time offset to the first device 110. The first device 110 may receive (270) the configuration. As used herein, the transmission time offset may also be referred to as a "first device 110-specific Koffset" or a "UE-specific Koffset".

[0105] In some example embodiments, the second device 120 may indicate the transmission time offset for scheduling after the transition via a DL MAC CE as defined in the tradition. Alternatively or additionally, in some example embodiments, the second device 120 may indicate the transmission time offset for scheduling after the transition via a physical downlink control channel (PDCCH) or RRC. This facilitates adjusting the UE-specific Koffset together with the UL grant after the transition.

[0106] In one example, based on the reported TA of the target NTN device 160, at a switch such as a satellite switch, the second device 120 can schedule the first device 110 based on the new TA. Alternatively or additionally, the second device 120 can schedule the first device 110 based on the new TA after the interruption length after the switch (such as satellite switch+interruption length). The interruption length can be predefined or configured. In one example, the interruption length can be the time for the first device 110 to resynchronize to the target NTN device 160.

[0107] The first device 110 may switch (275) the connection from the source target NTN device 130 to the target NTN device 160. After switching (275), the first device 110 may perform (280) transmission based on the received (270) configuration of the transmission time offset.

[0108] In some example embodiments, the PUSCH transmission may be delayed by Koffset compared to the transmission. Koffset may be the result of subtracting a first device 110-specific Koffset (indicated by the MAC CE) such as a UE-specific Koffset from a cell-specific Koffset (indicated by the SIB). The first device 110-specific Koffset such as a UE-specific Koffset may be a transmission time offset configured by the second device 120.

[0109] The cell-specific Koffset can be regarded as a rough value applied to all first devices in the cell, which can be greater than the maximum TA among all first devices. The UE-specific Koffset is the delta applied on it. Using the TA reported from the first device 110, it is possible to assist the network in configuring an appropriate UE-specific Koffset to the first device 110, which can reduce UL latency and improve scheduling efficiency. For example, the final Koffset is larger but close to the RTT between the first device 110 and the second device 120, instead of using the maximum UE-eNB RTT among all UEs. In other words, if no TA report is available, it is impossible for the NW to configure a UE-specific Koffset, and therefore the UE has to apply the final Koffset as the cell-specific Koffset.

[0110] Therefore, by configuring the transmission time offset (ie, Koffset specific to the first device 110), UL latency may be reduced and scheduling efficiency may be improved.

[0111] In order to ensure that the first device 110 has enough time to perform TA adjustment and UL processing delay, the timing of the scheduled transmission of the first device 110 needs to be greater than the actual transmission time of the first device 110 application.

[0112] Figure 5 An example diagram 500 illustrating scheduling time relationships according to some example embodiments of the present disclosure is shown. Figure 5 In the description, it is assumed that the first device 110 is implemented as a terminal device and the second device 120 is implemented as a network device. As shown in the figure, the timing of the scheduled UL transmission of the first device 110 (i.e., n+4+Koffset) needs to be greater than the actual transmission time applied by the first device 110 (i.e., n+TA+UL processing delay). In other words, (Koffset+4) needs to be greater than (TA+UL processing delay). The value of Koffset can be configured by the second device 120 based on predefined or configured conditions. An example condition may be Koffset>TA+UL processing delay-4. Under this condition, it can be ensured that the timing of the scheduled transmission of the first device 110 is greater than the actual transmission time applied by the first device 110.

[0113] Using the predicted TA information, the second device 120 can configure a transmission time offset (such as a UE-specific Koffset) based on the predicted TA and the condition that Koffset>TA+UL processing delay-4. It should be understood that such example conditions are only for illustrative purposes and do not imply any limitation. Any suitable condition or calculation can be applied to determine the transmission time offset based on the predicted TA. The scope of the present disclosure is not limited in this regard.

[0114] This solution enables the UE to report the predicted TA for the serving cell with the target satellite in the scenario of satellite switching without RACH. This is mandatory to avoid the failure of granted UL transmissions, as Koffset can be configured / adapted based on UE-specific RTT. By using predicted TA reporting for satellite switching without RACH in unchanged PCI scenario, the failure of scheduled UL transmissions after the switch can be avoided.

[0115] Figure 6 FIG. 6 is a flowchart showing an example method 600 implemented at a first device according to some example embodiments of the present disclosure. For discussion purposes, the method 600 will be described in detail in FIG. Figure 1A and Figure 1BThe angle of the first device 110 is described.

[0116] At block 610, the first device 110 determines a predicted timing advance associated with a target non-terrestrial network device before switching a connection from the source non-terrestrial network device to the target non-terrestrial network device. The source non-terrestrial network device serves the first device, and the target non-terrestrial network device serves the first device after switching.

[0117] At block 620, the first device 110 transmits information about the predicted timing advance to the second device before switching.

[0118] In some example embodiments, the method 600 further includes switching the connection from the source non-terrestrial network device to the target non-terrestrial network device without a random access procedure.

[0119] In some example embodiments, the method 600 further includes: transmitting to the second device at a first time point prior to the time window of the transition at least one of: information, a request for transmission of the information.

[0120] In some example embodiments, the method 600 further comprises: receiving a configuration of the time window from the second device.

[0121] In some example embodiments, method 600 further includes determining that a difference between a predicted timing advance associated with the target non-terrestrial network device and a reference timing advance associated with the source non-terrestrial network device is greater than or equal to a threshold; and based on the determination, transmitting information to a second device.

[0122] In some example embodiments, the information includes at least one of: a predicted timing advance associated with the target non-terrestrial network device, a reference timing advance associated with the source non-terrestrial network device, and a difference between the predicted timing advance and the reference timing advance.

[0123] In some example embodiments, the predicted timing advance is carried in a media access control control element, or the difference between the predicted timing advance and the reference timing advance is carried in at least one reserved bit in the media access control control element, and the at least one reserved bit indicates a ratio of the difference to a predetermined timing advance.

[0124] In some example embodiments, the method 600 further includes: receiving ephemeris information and a set of timing advance parameters of the target non-terrestrial network device from the second apparatus; and determining a predicted timing advance based on the ephemeris information and the set of timing advance parameters.

[0125] In some example embodiments, method 600 further includes receiving ephemeris information and a set of timing advance parameters from a second device at a second time point prior to a first time point, wherein at least one of the information and the transmission request for the information is transmitted to the second device at the first time point.

[0126] In some example embodiments, the method 600 further includes: receiving, from the second device, a configuration of an offset of the second time point relative to the first time point.

[0127] Figure 7 FIG. 7 is a flowchart of an example method 700 implemented at a second device according to some example embodiments of the present disclosure. For discussion purposes, the method 700 will be described in detail in FIG. Figure 1A and Figure 1B The perspective of the second device 120 is described.

[0128] At block 710, the second device 120 receives information about a predicted timing advance associated with a target non-terrestrial network device from a first device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device. The source non-terrestrial network device serves the first device, and after the switching, the target non-terrestrial network device serves the first device.

[0129] At block 720, the second device 120 determines a configuration of a transmission time offset for transmissions of the first device based on the information.

[0130] In some example embodiments, the method 700 further includes: receiving, from the first device at a first point in time prior to the time window of the conversion, at least one of: information, a request for transmission of the information.

[0131] In some example embodiments, the method 700 further comprises: determining the time window based on at least one of: a round trip time between the first device and the second device, a number of retransmissions, a scheduling request period; and transmitting a configuration of the time window to the first device.

[0132] In some example embodiments, the information includes at least one of: a predicted timing advance associated with the target non-terrestrial network device, a reference timing advance associated with the source non-terrestrial network device, and a difference between the predicted timing advance and the reference timing advance.

[0133] In some example embodiments, the predicted timing advance is carried in a media access control control element, or the difference between the predicted timing advance and the reference timing advance is carried in at least one reserved bit in the media access control control element, and the at least one reserved bit indicates a ratio of the difference to a predetermined timing advance.

[0134] In some example embodiments, the method 700 further includes transmitting the ephemeris information and the timing advance parameter set of the target non-terrestrial network device to the first apparatus.

[0135] In some example embodiments, method 700 further includes transmitting ephemeris information and a set of timing advance parameters to the first device at a second time point prior to the first time point, wherein at least one of the information and a request for transmission of the information is received from the first device at the first time point.

[0136] In some example embodiments, the method 700 further includes: transmitting, to the first device, a configuration of an offset of the second time point relative to the first time point.

[0137] In some example embodiments, the method 700 further comprises transmitting the configuration of the transmission time offset to the first device.

[0138] In some example embodiments, the second device is connected to at least one of the following: a source non-terrestrial network device before conversion, a target non-terrestrial network device, or the second device is located in at least one of the following: a source non-terrestrial network device before conversion, a target non-terrestrial network device.

[0139] In some example embodiments, the non-terrestrial network device includes at least one of the following: a satellite, a high altitude platform station.

[0140] In some example embodiments, a first device (eg, Figure 1A and Figure 1B The first device 110 in the method 600 may include a component for performing the corresponding operation of the method 600. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module. The first device may be implemented as or included in Figure 1A and Figure 1B In the first device 110.

[0141] In some example embodiments, a first device includes: a component for determining a predicted timing advance associated with a target non-terrestrial network device before switching a connection from a source non-terrestrial network device to the target non-terrestrial network device, the source non-terrestrial network device serving the first device, and after the switching, the target non-terrestrial network device providing service to the first device; and a component for transmitting information about the predicted timing advance to a second device before the switching.

[0142] In some example embodiments, the first apparatus further comprises means for switching the connection from the source non-terrestrial network device to the target non-terrestrial network device without a random access procedure.

[0143] In some example embodiments, the first device further comprises: means for transmitting to the second device at a first point in time prior to the time window of the transition at least one of: information, a request for transmission of information.

[0144] In some example embodiments, the first apparatus further comprises means for receiving a configuration of the time window from the second apparatus.

[0145] In some example embodiments, the first apparatus further comprises: means for determining that a difference between a predicted timing advance associated with a target non-terrestrial network device and a reference timing advance associated with a source non-terrestrial network device is greater than or equal to a threshold; and means for transmitting information to the second apparatus based on the determination.

[0146] In some example embodiments, the information includes at least one of: a predicted timing advance associated with the target non-terrestrial network device, a reference timing advance associated with the source non-terrestrial network device, and a difference between the predicted timing advance and the reference timing advance.

[0147] In some example embodiments, the predicted timing advance is carried in a media access control control element, or the difference between the predicted timing advance and the reference timing advance is carried in at least one reserved bit in the media access control control element, and the at least one reserved bit indicates a ratio of the difference to the predetermined timing advance.

[0148] In some example embodiments, the first apparatus further comprises: means for receiving ephemeris information and a set of timing advance parameters of the target non-terrestrial network device from the second apparatus; and means for determining a predicted timing advance based on the ephemeris information and the set of timing advance parameters.

[0149] In some example embodiments, the first device further comprises: means for receiving ephemeris information and a set of timing advance parameters from a second device at a second time point prior to the first time point, wherein at least one of the information and the request for transmission of information is transmitted to the second device at the first time point.

[0150] In some example embodiments, the first apparatus further comprises means for receiving, from the second device, a configuration of an offset of the second time point relative to the first time point.

[0151] In some example embodiments, the first apparatus further comprises means for performing the method 600 or other operations in some example embodiments of the first apparatus 110. In some example embodiments, the apparatus comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause execution of the first apparatus.

[0152] In some example embodiments, a second device (eg, Figure 1A and Figure 1B The second device 120 in the method 700 may include a component for performing the corresponding operation of the method 700. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module. The second device may be implemented as or included in Figure 1A and Figure 1B In the second device 120.

[0153] In some example embodiments, the second device includes means for receiving, from the first device, information about a predicted timing advance associated with a target non-terrestrial network device before switching a connection from a source non-terrestrial network device to a target non-terrestrial network device, the source non-terrestrial network device serving the first device, and the target non-terrestrial network device providing service to the first device after the switching; and means for determining a configuration of a transmission time offset for transmissions of the first device based on the information.

[0154] In some example embodiments, the second device further comprises: means for receiving at least one of: information, a request for transmission of information from the first device at a first point in time prior to the time window for the transition.

[0155] In some example embodiments, the second device further comprises: a component for determining the time window based on at least one of: a round trip time between the first device and the second device, a number of retransmissions, a scheduling request period; and a component for transmitting the configuration of the time window to the first device.

[0156] In some example embodiments, the information includes at least one of: a predicted timing advance associated with the target non-terrestrial network device, a reference timing advance associated with the source non-terrestrial network device, and a difference between the predicted timing advance and the reference timing advance.

[0157] In some example embodiments, the predicted timing advance is carried in a media access control control element, or the difference between the predicted timing advance and the reference timing advance is carried in at least one reserved bit in the media access control control element, and the at least one reserved bit indicates a ratio of the difference to the predetermined timing advance.

[0158] In some example embodiments, the second apparatus further comprises: means for transmitting ephemeris information and a set of timing advance parameters of the target non-terrestrial network device to the first apparatus.

[0159] In some example embodiments, the second apparatus further comprises means for transmitting ephemeris information and a set of timing advance parameters to the first apparatus at a second time point prior to the first time point, wherein at least one of the information and the request to transmit the information is received from the first apparatus at the first time point.

[0160] In some example embodiments, the second apparatus further comprises means for transmitting to the first equipment a configuration of an offset of the second time point relative to the first time point.

[0161] In some example embodiments, the second apparatus further comprises means for transmitting the configuration of the transmission time offset to the first apparatus.

[0162] In some example embodiments, the second device is connected to at least one of the following: a source non-terrestrial network device before conversion, a target non-terrestrial network device, or the second device is located in at least one of the following: a source non-terrestrial network device before conversion, a target non-terrestrial network device.

[0163] In some example embodiments, the non-terrestrial network device includes at least one of the following: a satellite, a high altitude platform station.

[0164] In some example embodiments, the second apparatus further comprises means for performing the method 700 or other operations in some example embodiments of the second apparatus 120. In some example embodiments, the apparatus comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause execution of the first apparatus.

[0165] Figure 8 8 is a simplified block diagram of a device 800 suitable for implementing an example embodiment of the present disclosure. The device 800 may be provided for implementing a communication device, such as Figure 1A and Figure 1B The first device 110 or the second device 120 is shown. As shown in the figure, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor 810, and one or more communication modules 840 coupled to the processor 810.

[0166] The communication module 840 is used for two-way communication. The communication module 840 has one or more communication interfaces to support communication with one or more other modules or devices. The communication interface may represent any interface necessary for communication with other network elements. In some example embodiments, the communication module 840 may include at least one antenna.

[0167] Processor 810 may be of any type suitable for the local technology network, and may include one or more of the following: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture, as non-limiting examples. Device 800 may have multiple processors, such as application specific integrated circuit chips, which are time-slaved to the clock of a synchronized master processor.

[0168] The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 824, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), optical disk, laser disk, and other magnetic storage and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 822 and other volatile memories that do not persist over the duration of a power outage.

[0169] The computer program 830 includes computer executable instructions executed by the associated processor 810. The instructions of the program 830 may include instructions for performing the operations / actions of some example embodiments of the present disclosure. The program 830 program 930 may be stored in a memory, such as ROM 824. The processor 810 may perform any suitable actions and processes by loading the program 830 into the RAM 822.

[0170] The exemplary embodiments of the present disclosure may be implemented by means of 830 so that the device 800 may perform the operations described in reference to Figures 2 to 7 Any process of the present disclosure discussed. The exemplary embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0171] In some example embodiments, the program 830 may be tangibly embodied in a computer-readable medium that may be included in the device 800 (such as in the memory 820) or in other storage devices accessible to the device 800. The device 800 may load the program 830 from the computer-readable medium to the RAM 822 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. The term "non-transitory" as used herein is a limitation of the medium itself (i.e., tangible, not a signal), not a limitation on data storage persistence (e.g., RAM versus ROM).

[0172] Fig. 9 An example of a computer readable medium 900 is shown which may be in the form of a CD, DVD or other optical storage disk. The computer readable medium 900 has a program 830 stored thereon.

[0173] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the boxes, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0174] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer-readable medium (such as a non-transient computer-readable medium). The computer program product includes computer executable instructions, such as those included in a program module executed in a device on a target physical or virtual processor to perform any method as described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of the program modules can be combined or split between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0175] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. The program code can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0176] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0177] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or apparatuses, or any suitable combination of the foregoing. More specific examples of computer readable storage media would include an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0178] In addition, although operations are depicted in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in sequence, or to perform all of the operations shown, to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the present disclosure, but as descriptions of features that may be specific to a particular embodiment. Unless explicitly stated, certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, unless explicitly stated, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0179] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first device for communication, comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the first device to: determining a predicted timing advance associated with a target non-terrestrial network device prior to switching a connection from a source non-terrestrial network device to the target non-terrestrial network device, the source non-terrestrial network device serving the first apparatus, and after the switching, the target non-terrestrial network device serving the first apparatus; as well as Prior to the switching, information about the predicted timing advance is transmitted to a second device.

2. The first device according to claim 1, wherein the first device: The connection is switched from the source non-terrestrial network device to the target non-terrestrial network device without a random access procedure.

3. The first device according to claim 1 or claim 2, wherein the first device: At least one of the following is transmitted to the second device at a first time point before the time window prior to the switching: the information, and a request for transmission of the information.

4. The first device according to claim 3, wherein the first device is further configured to: A configuration of the time window is received from the second device.

5. The first device according to claim 1 or claim 2, wherein the first device: determining that a difference between the predicted timing advance associated with the target non-terrestrial network device and a reference timing advance associated with the source non-terrestrial network device is greater than or equal to a threshold; and Based on the determination, the information is transmitted to the second device.

6. The first device according to claim 1 or claim 2, wherein the information comprises at least one of the following: the predicted timing advance associated with the target non-terrestrial network device, A reference timing advance associated with the source non-terrestrial network device and a difference between the predicted timing advance and the reference timing advance.

7. The first device according to claim 6, wherein The predicted timing advance is carried in a medium access control element, or The difference between the predicted timing advance and the reference timing advance is carried in at least one reserved bit in a medium access control control element, and the at least one reserved bit indicates a ratio of the difference to a predetermined timing advance difference.

8. The first device according to claim 1 or claim 2, wherein the first device: receiving ephemeris information and a timing advance parameter set of the target non-terrestrial network device from the second apparatus; and The predicted timing advance is determined based on the ephemeris information and the set of timing advance parameters.

9. The first device according to claim 8, wherein the first device is further configured to: receiving the ephemeris information and the timing advance parameter set from the second device at a second time point before the first time point, At the first time point, at least one of the following is transmitted to the second device: the information, and a request for transmitting the information.

10. The first device according to claim 9, wherein the first device is further configured to: A configuration of an offset of the second time point relative to the first time point is received from the second device.

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