Method and apparatus for wireless communication in a non-terrestrial based network - Patents.com

Abstract

The present application relates to a method and apparatus for wireless communication in a non-terrestrial based network. One embodiment of the present disclosure provides a Radio Access Network (RAN) node, the RAN node including a transceiver and a processor, the processor being configured to determine first time information associated with a neighboring RAN node of the RAN node and transmit the first time information to a user equipment (UE), the first time information including at least one of a first epoch time associated with the neighboring RAN node or a first validity time associated with the neighboring RAN node.

Description

[Technical field]

[0001] The present disclosure relates to wireless communication technologies, and more particularly, to a method and apparatus for wireless communication in a non-terrestrial based network (NTN), e.g., for time-related status determination of neighboring Radio Access Network (RAN) nodes in the NTN. [Background technology]

[0002] The ephemeris and common timing advance (TA) of the serving satellite or high altitude platform station (HAPS) are required at the user equipment (UE) for uplink time synchronization. The ephemeris of neighboring satellites or HAPS is also required at the UE for propagation delay estimation to assist in measurement window (or gap) configuration and / or time-based cell reselection.

[0003] In order to calculate the current accurate and valid position of the neighboring satellite or HAPS, and thus the propagation delay between the UE and the neighboring satellite or HAPS, the UE needs to know the epoch time and validity time duration associated with the ephemeris of the neighboring satellite or HAPS. Meanwhile, when uplink synchronization to the neighboring satellite or HAPS is required (e.g., handover to a neighboring cell belonging to the neighboring satellite or HAPS), the UE also needs to know the epoch time and validity duration associated with the neighboring satellite or HAPS, the common TA, the feeder link delay or speed, etc. Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is quite difficult for a UE to obtain the above time-related status of neighboring satellites or HAPS, and it is desirable to provide a solution to solve the above problem. [Means for solving the problem]

[0005] One embodiment of the present disclosure provides a Radio Access Network (RAN) node, including a transceiver and a processor, the processor configured to determine first time information associated with a neighboring RAN node of the RAN node and transmit the first time information to a UE, the first time information including at least one of a first epoch time associated with the neighboring RAN node or a first validity time associated with the neighboring RAN node.

[0006] In some embodiments, the first time information is determined based on second time information of a neighboring RAN node, and the second time information may include at least one of the following: a second epoch time associated with the neighboring RAN node, or a second validity time associated with the neighboring RAN node.

[0007] In some embodiments, the second time information is pre-stored in the RAN node or received from the neighbouring RAN node in response to a request from the RAN node to the neighbouring RAN node.

[0008] In some embodiments, the request may include at least one of an indication of requesting a portion of the second time information or all of the second time information, an identification of a neighboring RAN node, or a preferred format of the second time information.

[0009] In some embodiments, the first temporal information is represented in a first format and the second temporal information is represented in a second format, and the processor is further configured to convert the second temporal information in the second format to the first temporal information in the first format.

[0010] In some embodiments, the first time information is represented by one or more different values ​​compared to the second time information.

[0011] In some embodiments, at least one of the first epoch time or the first validity time is related to at least one of an ephemeris of a neighboring RAN node, a common TA of the neighboring RAN node, or a feeder link propagation delay of the neighboring RAN node.

[0012] In some embodiments, the first time information may further include a first reference time point for at least one of the first epoch time or the first valid time.

[0013] In some embodiments, the first time information is transmitted to the UE by a system information (SI) broadcast, an on-demand SI, or a dedicated signaling.

[0014] In some embodiments, the first time information indicates at least one of the following: the first epoch time has the same value as a third epoch time associated with the RAN node, and the third epoch time is associated with at least one of the RAN node's ephemeris or the RAN node's common TA; or the first validity time has the same value as a third validity time associated with the RAN node, and the third validity time is associated with at least one of the RAN node's ephemeris or the RAN node's common TA.

[0015] Another embodiment of the present disclosure provides a UE, which may include a transceiver and a processor, wherein the processor is configured to receive, from the RAN node, first time information associated with a neighboring RAN node of the RAN node; and determine a time-related status of the neighboring RAN node based on the first time information, wherein the first time information includes at least one of a first epoch time associated with the neighboring RAN node or a first validity time associated with the neighboring RAN node.

[0016] In some embodiments, at least one of the first epoch time or the first validity time is related to at least one of the following: an ephemeris of a neighboring RAN node, a common TA of the neighboring RAN node, or a feeder link propagation delay of the neighboring RAN node.

[0017] In some embodiments, the first time information may further include a first reference time point for at least one of the first epoch time or the first valid time.

[0018] In some embodiments, the first time information is received by SI broadcast, on-demand SI, or dedicated signaling.

[0019] In some embodiments, the time related status of the neighboring RAN nodes may include at least one of the following: at least one of the ephemeris, the common TA, or the feeder link propagation delay at the first epoch time; at least one of the ephemeris, the common TA, or the feeder link propagation delay being valid; at least one of the ephemeris, the common TA, or the feeder link propagation delay at a given time; coordinates of the neighboring RAN node at a given time; orbital position of the neighboring RAN node at a given time; a validity timer for a neighboring RAN node parameter value that is started when the first time information is received; a length of the validity timer from the time of receipt to the first validity time; the first epoch time has the same value as a third epoch time associated with the RAN node, and the third epoch time is associated with at least one of the ephemeris of the RAN node or the common TA of the RAN node; or the first validity time has the same value as a third validity time associated with the RAN node, and the third validity time is associated with at least one of the ephemeris of the RAN node or the common TA of the RAN node.

[0020] In some embodiments, where the first time information may include a first validity time, the processor is further configured to at least one of: discard the received first time information associated with the neighboring RAN node upon expiration of the first validity time; discard a determined time-related status based on the first time information upon expiration of the first validity time; or request an update of the first time information associated with the neighboring RAN node upon expiration of the first validity time.

[0021] Yet another embodiment of the present disclosure provides a method implemented by a RAN node, the method including: determining first time information associated with a neighboring RAN node of the RAN node; and transmitting the first time information to a UE, the first time information including at least one of a first epoch time associated with the neighboring RAN node or a first validity time associated with the neighboring RAN node.

[0022] In some embodiments, the first time information is determined based on second time information of a neighboring RAN node, and the second time information may include at least one of the following: a second epoch time associated with the neighboring RAN node, or a second validity time associated with the neighboring RAN node.

[0023] In some embodiments, the second time information is pre-stored in the RAN node or received from the neighbouring RAN node in response to a request from the RAN node to the neighbouring RAN node.

[0024] In some embodiments, the request may include at least one of an indication of requesting a portion of the second time information or all of the second time information, an identification of a neighboring RAN node, or a preferred format of the second time information.

[0025] In some embodiments, the first time information is represented in a first format and the second time information is represented in a second format, and the method may further include converting the second time information in the second format to the first time information in the first format.

[0026] In some embodiments, the first time information is represented by one or more different values ​​compared to the second time information.

[0027] In some embodiments, at least one of the first epoch time or the first validity time is related to at least one of an ephemeris of a neighboring RAN node, a common TA of the neighboring RAN node, or a feeder link propagation delay of the neighboring RAN node.

[0028] In some embodiments, the first time information may further include a first reference time point for at least one of the first epoch time or the first valid time.

[0029] In some embodiments, the first time information is transmitted to the UE by SI broadcast, on-demand SI, or dedicated signaling.

[0030] In some embodiments, the first time information indicates at least one of the following: the first epoch time has the same value as a third epoch time associated with the RAN node, and the third epoch time is associated with at least one of the RAN node's ephemeris or the RAN node's common TA; or the first validity time has the same value as a third validity time associated with the RAN node, and the third validity time is associated with at least one of the RAN node's ephemeris or the RAN node's common TA.

[0031] Yet another embodiment of the present disclosure provides a method, implemented by a UE, that may include receiving, from a RAN node, first time information associated with a neighboring RAN node of the RAN node; and determining a time-related status of the neighboring RAN node based on the first time information, where the first time information includes at least one of a first epoch time associated with the neighboring RAN node or a first validity time associated with the neighboring RAN node.

[0032] In some embodiments, at least one of the first epoch time or the first validity time is related to at least one of the following: an ephemeris of a neighboring RAN node, a common TA of the neighboring RAN node, or a feeder link propagation delay of the neighboring RAN node.

[0033] In some embodiments, the first time information may further include a first reference time point for at least one of the first epoch time or the first valid time.

[0034] In some embodiments, the first time information is received by SI broadcast, on-demand SI, or dedicated signaling.

[0035] In some embodiments, the time related status of the neighboring RAN nodes may include at least one of the following: at least one of the ephemeris, the common TA, or the feeder link propagation delay at the first epoch time; at least one of the ephemeris, the common TA, or the feeder link propagation delay being valid; at least one of the ephemeris, the common TA, or the feeder link propagation delay at a given time; coordinates of the neighboring RAN node at a given time; orbital position of the neighboring RAN node at a given time; a validity timer for a neighboring RAN node parameter value that is started when the first time information is received; a length of the validity timer from the time of receipt to the first validity time; the first epoch time has the same value as a third epoch time associated with the RAN node, and the third epoch time is associated with at least one of the ephemeris of the RAN node or the common TA of the RAN node; or the first validity time has the same value as a third validity time associated with the RAN node, and the third validity time is associated with at least one of the ephemeris of the RAN node or the common TA of the RAN node.

[0036] In some embodiments, where the first time information may include a first validity time, the method may further include at least one of discarding the received first time information associated with the neighboring RAN node upon expiration of the first validity time, discarding a determined time-related status based on the first time information upon expiration of the first validity time, or requesting an update of the first time information associated with the neighboring RAN node upon expiration of the first validity time.

[0037] To explain how the advantages and features of the present application can be obtained, the application will be described by reference to specific embodiments thereof that are illustrated in the accompanying drawings. These drawings depict only typical embodiments of the present application and therefore should not be considered as limiting the scope thereof. [Brief description of the drawings]

[0038] [Figure 1A] FIG. 2 illustrates an example satellite ephemeris format according to some embodiments of the present disclosure. [Figure 1B] FIG. 2 illustrates an example satellite ephemeris format according to some embodiments of the present disclosure. [Figure 2A] FIG. 2 illustrates serving satellite information related to epoch time and validity duration in accordance with some embodiments of the present disclosure. [Figure 2B] FIG. 2 illustrates serving satellite information related to epoch time and validity duration in accordance with some embodiments of the present disclosure. [Figure 2C] FIG. 2 illustrates serving satellite information related to epoch time and validity duration in accordance with some embodiments of the present disclosure. [Diagram 3] A diagram showing a method for a UE to obtain the epoch time and valid duration of a neighboring RAN node. [Figure 4] FIG. 2 illustrates a method for a UE to obtain epoch time and valid duration of a neighboring RAN node according to some embodiments of the present disclosure. [Diagram 5] 4 is a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure. [Figure 6] FIG. 1 is a block diagram of an exemplary apparatus according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The detailed description in the accompanying drawings is intended to illustrate the presently preferred embodiments of the invention and is not intended to represent the only form in which the invention may be practiced. It is to be understood that the same or equivalent functions may be performed by different embodiments which are intended to be encompassed within the spirit and scope of the invention.

[0040] Although operations are shown in the figures in a particular order, those skilled in the art will readily appreciate that such operations need not be performed in the particular order shown, or in sequential order, or that not all illustrated operations need be performed, and one or more operations may be omitted, to achieve desirable results. Additionally, the figures may depict one or more exemplary processes generally in the form of a flow diagram. However, other operations not shown may be incorporated into the generally depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some environments, multitasking and parallel processing may be advantageous.

[0041] Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. For ease of understanding, the embodiments are provided under specific network architectures and new service scenarios, such as Third Generation Partnership Project (3GPP®) 5G (NR), 3GPP® Long Term Evolution (LTE), etc. With the development of network architectures and new service scenarios, it is contemplated that all embodiments of the present disclosure are also applicable to similar technical problems, and further, the terms described in the present disclosure may change, which does not affect the principle of the present disclosure.

[0042] NTN refers to a network, or a segment of a network, that uses radio frequency (RF) resources onboard a satellite or HAPS. The satellites in an NTN may be geostationary earth orbiting (GEO) satellites that have a fixed position relative to the Earth, or low earth orbiting (LEO) satellites that orbit the Earth. The HAPS in an NTN may be an aircraft or a balloon. In 3GPP Rel-17, NTN using the NR air interface is discussed in the work item "Solutions for NR to support NTN", and NTN using the LTE air interface for IoT UEs is discussed in the work item "Study on NB-IoT / eMTC support for NTN". In an NTN, both the satellites and HAPS, as well as the terrestrial BS or access node (AN), may be referred to as RAN nodes. In some embodiments of the present disclosure, the satellite or HAPS may only act as an access node, while in some other embodiments of the present disclosure, the satellite or HAPS may act as a BS.

[0043] In NTNs, especially those with LEO, fast moving satellites, ephemeris data is used to indicate the orbit and position coordinates of the satellites. The serving satellite ephemeris may be indicated to the UE to calculate the distance to the satellite so that the propagation delay can be determined, which is crucial for uplink time synchronization in NTNs. The ephemeris may also be used to calculate the satellite velocity relative to the UE, which is crucial for uplink frequency synchronization. It is the same for HAPS in NTNs.

[0044] 1A and 1B respectively show two exemplary satellite ephemeris formats according to some embodiments of the present disclosure. For satellite systems with satellites, either or both formats may be applied, but for HAPS without satellite orbits, only the position and velocity state vector ephemeris format is applied.

[0045] 1A, a satellite 102 orbits the Earth. The origin of the coordinate system is the center of the Earth. The coordinate system has three axes: an x-axis, a y-axis, and a z-axis.

[0046] FIG. 1A shows the ephemeris format of the position and velocity state vector, where the satellite ephemeris is represented by the position and velocity state vector {x, y, z, Δx, Δy, Δz}, x is the coordinate value on the x-axis, y is the coordinate value on the y-axis, z is the coordinate value on the z-axis, Δx is the velocity value on the x-axis, Δy is the velocity value on the y-axis, Δz is the velocity value on the z-axis.

[0047] The payload size for the position and velocity state vector ephemeris format is 17 bytes, i.e. 17 x 8 = 136 bits. Of the 136 bits, 78 bits are for position in meters (m), i.e. parameters {x, y, z}. The position range is determined by GEO with a range of -42200 kilometers (km) to +42200 km. The quantization step is 1.3 m for position. 54 bits are for velocity with units of meters per second (m / s), the velocity range is determined by LEO with an altitude of 600 km with a range of -8000 m / s to +8000 m / s.

[0048] FIG. 1B shows the ephemeris format of the orbital parameters. That is, the satellite ephemeris is expressed by the orbital parameters. In FIG. 1B, the satellite 102 is a GEO satellite with a fixed position relative to the Earth. The origin of the coordinate system is the center of the Earth. The coordinate system has three axes, namely, x-axis, y-axis, and z-axis. The payload size for the ephemeris format of the position and velocity state vector is 18 bytes, that is, 18×8=144 bits. The orbital parameters include: 1) Semi-major axis α, the unit of the semi-major axis is meters, the bit size for the semi-major axis is 33 bits, and the value of α ranges from 6500 km to 43000 km. 2) Eccentricity e, the bit size for eccentricity is 19 bits, and the value of eccentricity is not greater than 0.015, i.e. ≦0.015. 3) Argument of periapsis ω, the unit of the periapsis argument is rad, the bit size of the periapsis argument is 24 bits, and the value of ω ranges from 0 to 2π. 4) Longitude of ascending node Ω, the unit of ascending node longitude is rad, the bit size of ascending node longitude is 21 bits, and the value of Ω ranges from 0 to 2π. 5) inclination i, the unit of inclination is rad, the bit size of inclination is 20 bits, and the value of i ranges from -π / 2 to +π / 2. 6) Mean anomaly M in epoch time, the unit of mean anomaly is rad, the bit size of mean anomaly is 24 bits, and the value of M ranges from 0 to 2π.

[0049] For a moving satellite or HAPS, some or all of the parameters in the ephemeris vary with time. Given a satellite (or HAPS) ephemeris associated with a time point (i.e., epoch time), the UE can calculate the satellite (or HAPS) position at the current or future time point as long as it is valid. To ensure the accuracy and validity of the UE calculation, 3GPP RAN1 has confirmed that it is necessary to provide the UE with the epoch time and validity duration of the serving satellite (or HAPS) ephemeris. Other information related to uplink time synchronization, including the common TA and its rate of change, may also be indicated along with the epoch time and validity duration to ensure the accuracy and validity of the uplink time synchronization.

[0050] 2A-2C illustrate serving satellite information related to epoch time and validity duration according to some embodiments of the present disclosure.

[0051] There are three components shown in Figure 2A: UE 201, satellite 202, and BS 203, where BS 203 is the serving BS of UE 201 and satellite 202 is the serving satellite of UE 201. The link between BS 203 and satellite 202 is called the feeder link, and the link between satellite 202 and UE 201 is called the service link. Point 1 refers to the uplink (UL) synchronization reference point, and point 2 refers to the epoch time. TA1 is half the network (NW) corrected TA, which is a constant value, and TA2 is the time T tx TA3 is half of the common TA at time T tx The TA is half of the specific UE's TA in

[0052] Time T tx In the above, the network, e.g., BS 203, transmits at least one of a serving satellite ephemeris or a common TA related to an epoch time and a validity duration to the UE 201, and the UE 201 receives a time T rx Receive it at time T rxis approximately equal to T rx = T tx + T tx Service link delay in +T tx Feeder link delay in

[0053] The service link delay (i.e., TA3) is T tx is half of the UE-specific TA at tx TA1 (a constant value) and TA2) in are half of the common TA and the network corrected TA. The common TA and the network corrected TA are divided by a reference point between the BS 203 and the satellite 202, which is called the uplink time synchronization reference point, i.e., point 1.

[0054] Regarding the details of presenting the epoch time and validity time of the serving satellite, 3GPP RAN1 has reached the following agreement.

[0055] [Table 1]

[0056] According to the above agreement, the epoch time, i.e. point 2 in FIG. 2A, may be explicitly given to the UE 201 by SIB1 or dedicated signaling, or may be implicitly known as the end of the SI window.

[0057] That is, the epoch time, i.e., point 2, is indicated by the system frame number (SFN) and subframe number signaled together with the assistance information.

[0058] Referring to FIG. 2B, the epoch time, point 2, is the end of the SI window during which SI messages are transmitted.

[0059] As shown in FIG. 2C, upon receiving at least one of the serving satellite ephemeris or the common TA associated with the epoch time and the validity duration, the UE considers that the received parameter value is associated with the epoch time and the indicated validity duration begins therefrom. As shown in FIG. 2C, using the received information, the UE determines the time T during the validity duration. cal According to the movement of at least one satellite or UE in the satellite map, the latest serving satellite position as well as its common TA can be calculated.

[0060] In detail, at time T cal At time T cal At least one of the ephemeris of the serving satellite or the common TA at time T tx The calculation is based on at least one of the ephemeris or the common TA in

[0061] For uplink frequency synchronization, there is no final RAN1 agreement related to epoch time and valid duration, but it is expected that epoch time and valid duration are also important to calculate the exact valid frequency point or band at a given time, taking into account the large Doppler shift caused by satellite (or HAPS) motion.

[0062] From the RAN1 perspective, the ephemeris of the serving satellite (or HAPS) and the common TA are required at the UE for uplink time synchronization. From the RAN2 perspective, the ephemeris of the neighboring satellite (HAPS) is also required at the UE for propagation delay estimation to assist in measurement window (or gap) configuration and / or time-based cell reselection, etc.

[0063] In order to calculate the current accurate and valid position of the neighboring satellite, and thus determine the propagation delay between the UE and the neighboring satellite (or HAPS), the UE needs to know the epoch time and validity duration associated with the ephemeris of the neighboring satellite (or HAPS). Meanwhile, when uplink synchronization to the neighboring satellite (or HAPS) is required (e.g., handover to a neighboring cell belonging to the neighboring satellite), the UE also needs to know the time-related status of the neighboring satellite (or HAPS), such as the epoch time and validity duration associated with the common TA, the feeder link delay or speed, etc.

[0064] 3 illustrates a method for a UE to obtain the epoch time and valid duration of a neighboring RAN node according to some embodiments of the present disclosure. The neighboring RAN node may be a satellite or a HAPS in the NTN, and a satellite is illustrated herein as an example. The following illustrated solution for a satellite is also applicable to a HAPS.

[0065] 3 shows a UE 301, a serving satellite 302A of the UE 301, a neighboring satellite 302B of the UE 301, a serving BS 303A of the UE 301, and a neighboring BS 303B of the UE 301. The coverage area A is covered by the serving satellite 302A, and the coverage area B is covered by the neighboring satellite 302B. Although the serving satellite 302A and the serving BS 303B are shown separately in FIG. 3, it is well known to those skilled in the art that they can be combined into one, for example, the serving satellite 302A acts as a BS by itself. The same is true for the neighboring satellite 302B and the neighboring BS 303B. In other words, in Figure 3, the serving BS 303A (or neighboring BS 303B) and the serving satellite 302A (or neighboring satellite 302B) are in different locations or devices, but in some other scenarios, the serving BS 303A (or neighboring BS 303B) and the serving satellite 302A (or neighboring satellite 302B) may be in the same location or device. In addition, the serving satellite 302A and the neighboring satellite 302B may be neighboring satellites, which may be referred to as other relationships, such as nearby satellites.

[0066] The serving satellite 302A may broadcast SI to UEs in coverage A, and the SI may include the epoch time and validity duration of the serving satellite, i.e., the epoch time and validity duration of the serving satellite 302A. To obtain the epoch time and validity duration of a neighboring RAN node, e.g., the neighboring satellite 302B, the UE 301 may need to satisfy the following conditions: 1) Coverage by nearby RAN nodes, e.g., satellites or HAPS; 2) configured with appropriate measurement gaps and SSB Measurement Timing Configuration (SMTC) windows; and 3) If a neighboring RAN node, e.g., a satellite or HAPS, uses a different Radio Access Technology (RAT) than the serving RAN node, measure the timing deviation between the two types of frames in the configured SFN and frame boundary timing difference (SFTD) window.

[0067] Regarding condition 1), in addition to being covered by the serving satellite (or HAPS, the same below), the UE needs to be covered by the neighboring satellite at the same time. That is, in FIG. 3, the UE 301 needs to be located within the intersection area of ​​coverage A and coverage B. However, under the quasi-earth fixed scenario, the neighboring satellite only starts covering the area of ​​the serving satellite when the serving satellite stops covering. That also applies to the discontinuous coverage scenario of a sparse satellite constellation. That is, the UE cannot be covered by both the serving satellite and the neighboring satellite at the same time under the quasi-earth fixed scenario.

[0068] Regarding condition 2), to perform an RF switch for reception from neighboring satellites, the UE needs to be configured with measurement gaps and SMTC. However, the network will not configure the appropriate measurement gaps or SMTC windows without knowledge of the propagation delays between the UE and the neighboring satellites, which need to be calculated based on the ephemeris of the neighboring satellites.

[0069] Regarding condition 3), if the neighboring satellite uses a different RAT (e.g., NR and LTE) than the serving satellite, the UE needs to measure the timing offset between the two types of frames in the configured SFTD window. As explained in RAN2, the network will not configure a proper SFTD window without knowledge of the propagation delay between the UE and the neighboring satellite.

[0070] Furthermore, even if conditions 1), 2), and 3) are met (e.g., a UE in an Earth moving scenario is simultaneously configured with appropriate measurement gaps and SMTC / SFTD windows), the UE still needs to receive at least the Master Information Block (MIB) and SIB1 of a neighboring satellite if the required information is included in SIB1, and may need to consume more power to receive other SIBs that contain the required information. In some other embodiments of the present application, the satellite ephemeris and other related information may be included in a new SIB (e.g., SIBx) other than SIB1, in which case the UE needs to receive the MIB, SIB1, and SIBx, which is less efficient in power consumption.

[0071] Similarly, if uplink synchronization to a neighboring RAN node, e.g., a satellite or HAPS, is required, it may be impossible or inefficient for the UE to directly acquire the common TA, feeder link delay or speed of the neighboring RAN node from the neighboring RAN node's broadcast.

[0072] In addition, the neighboring satellite (or HAPS) information may be represented in a frame format, where the subframe number is used instead of absolute UTC time. Format conversion may also be required when the neighboring RAN node uses a different RAT than the serving RAN node.

[0073] Therefore, the embodiments of the present disclosure propose a solution to provide time information (including at least one of epoch time or validity time) related to a neighboring RAN node, e.g., a neighboring satellite or a neighboring HAPS, to a UE by a serving RAN node, e.g., a serving BS, which is not limited by the above conditions. Furthermore, the time information may be provided by the serving RAN node with necessary processing (e.g., format conversion), allowing the UE to obtain the time information without the coverage of the neighboring RAN node and directly use the time information for calculation.

[0074] FIG. 4 illustrates a method for a UE to obtain epoch times and valid durations of neighboring RAN nodes according to some embodiments of the present disclosure.

[0075] 4 shows a UE 401, a serving satellite 402A of the UE, a neighboring satellite 402B of the UE 401, a serving BS 403A, and a neighboring BS 403B. A coverage area A is covered by the serving satellite 402A, and a coverage area B is covered by the neighboring satellite 402B. In FIG. 4, the serving BS 403A (or the neighboring BS 403B) and the serving satellite 402A (or the neighboring satellite 402B) are in different locations or devices, but in some other scenarios, the serving BS 403A (or the neighboring BS 403B) and the serving satellite 402A (or the neighboring satellite 402B) may be in the same location or device.

[0076] The serving BS 403A determines time information 4002 of the neighboring satellite 402B and transmits it to the UE 401. The time information 4002 may be determined based on time information 4001 from the neighboring BS 403B or a core network (CN) entity, or the time information 4002 is pre-stored in the serving BS 403A.

[0077] In the remainder of this disclosure, for simplicity and clarity, the time information 4002 of the neighboring satellite or HAPS will be referred to as first time information and the time information 4001 from the BS 403B or CN entity or pre-stored will be referred to as second time information.

[0078] In this way, UE 401 can acquire the time information of nearby satellite 402B even if the above conditions 1) to 3) are not met.

[0079] FIG. 5 illustrates a flowchart of an example procedure for wireless communication according to some embodiments of the present disclosure.

[0080] 5 shows three components: a UE, a RAN node 1, e.g., a satellite, and a RAN node 2, e.g., a terrestrial BS or a satellite or a CN entity acting as a BS. The RAN node 2 refers to a neighboring node of the RAN node 1, is a RAN node containing time information required by the RAN node 1 (or a UE in the coverage of the RAN node 1), and has second time information. The second time information may include at least one of the following: 1) a second epoch time associated with RAN node 2's ephemeris, common TA, or feeder link propagation delay; 2) a second validity time associated with the ephemeris, common TA, or feeder link propagation delay of RAN node 2; or 3) At least one of a second reference time point for a second epoch time or a second validity time associated with the RAN node 2.

[0081] In some scenarios, RAN node 1 may not have second time information related to RAN node 2. In operation 501, if there is a direct interface between RAN node 1 and RAN node 2, e.g., a BS-to-BS interface such as an S1 interface in LTE or an NG interface in NR, RAN node 1 may send a request to RAN node 2.

[0082] If there is no direct interface, the RAN node 1 may send a request to the CN entity to request second time information related to the RAN node 2 from the CN entity.

[0083] The request may include at least one of the following: 1) an indication of requesting some or all of second time information related to the RAN node 2; 2) the identity of RAN node 2, or 3) A preferred format of the second time information relating to the RAN node 2.

[0084] In operation 502, after receiving the request, the RAN node 2 or the CN entity transmits second time information related to the RAN node 2 to the RAN node 1.

[0085] The second time information related to the RAN node 2 may include at least one of a second epoch time associated with the ephemeris, a common TA, or a feeder link propagation delay of the RAN node 2, or may include at least one of a second valid time associated with the ephemeris, a common TA, or a feeder link propagation delay of the RAN node 2, or may include at least one of a second epoch time associated with the ephemeris, a second valid time associated with the ephemeris, a common TA, or a feeder link propagation delay of the RAN node 2.

[0086] In addition, the second time information may include at least one of a second reference time point for the second epoch time or a second validity time associated with the RAN node 2. If the second time information does not include a second reference time point, the RAN node 1 assumes that the second reference time point of the RAN node 2 is the same as that of the RAN node 1.

[0087] If the request from the RAN node 1 includes a preferred format of the second time information related to the RAN node 2, the RAN node 2 or the CN entity may convert the format of the second time information related to the RAN node 2 to the preferred format and send the second time information in the preferred format to the RAN node 1 in response.

[0088] The format conversion may include converting the second time information from a relative time format to an absolute time format. In the relative time format, the time value is represented by frame, subframe, and slot numbers. For example, the time value may have a length of 500 frames, 3 subframes, and 1 slot. In the absolute time format, the time value is represented in milliseconds (ms). For example, the time value may have a length of 1000 ms.

[0089] The second time information related to the RAN node 2 represented by frames, subframes, and slots may include: 1) The second epoch time, T e2,frame and may be represented by at least one of three integers, where a first integer represents a frame number of the second epoch time and ranges from 0 to 1023 (i.e., integer(0..1023)), a second integer represents a subframe number of the second epoch time and ranges from 0 to 9 (i.e., integer(0..9)), and a third integer represents a slot number of the second epoch time and ranges from 0 to 2 μ -1 (i.e., integers (0..2 μ-1), where μ_RN2=0,1,2,3,4 correspond to subcarrier spacings (SCS) of 15, 30, 60, 120, and 240 kHz for NR and μ=1 for LTE. The second epoch time, T e2,frame , 2) A second valid time, T, which may be similarly expressed as a second epoch time using at least one of three integers. v2,frame ,or 3) A second uplink time synchronization reference point, T, having units of milliseconds. ref,RN2 .

[0090] RAN node 1 receives a second epoch time associated with RAN node 2 (i.e., T e2,UTC ) or the second effective time (i.e., T v2,UTC ). The second epoch time and the second validity time are integers having a range from 0 to 549755813887 ms, i.e. integer(0..549755813887).

[0091] The format conversion is calculated as follows: T e2,UTC = T ref,RN2 + (10×T e2,frame frame number) + T e2,frame Subframe number of + (2 -μ ×T e2,frame slot number), and T v2,UTC = T ref,RN2 + (10×T v2,frame frame number) + T v2,frame Subframe number of + (2 -μ ×T v2,frame slot number).

[0092] Parameter T e2,frame or T v2,framemay include frame, subframe, and slot numbers, frame and subframe numbers, frame numbers only, or other combinations of frame, subframe, and slot numbers, depending on its accuracy requirements.

[0093] In some other scenarios, RAN node 1 may have the second time information related to RAN node 2 pre-stored in RAN node 1. For example, if the neighboring satellite or HAPS and the serving satellite (or HAPS) belong to the same BS, the serving BS already has the second time information related to the neighboring satellite or HAPS. In another example, the serving BS and the neighboring BS related to the neighboring satellite or HAPS are in the same network (e.g., the same public land mobile network (PLMN)). With reference to FIG. 4, BS 403A and BS 403B are all in the same network, in which case BS 403A may pre-store the second time information related to satellite 402B.

[0094] Based on the second time information associated with the RAN node 2, the RAN node 1 determines first time information also associated with the RAN node 2, and transmits the first time information to the UE.

[0095] Because the first time information and the second time information are in different formats, the determination may include a conversion of the different formats. The format conversion may include the following types: 1) Absolute format to absolute format, 2) Absolute to relative format, 3) Relative to absolute format, 4) Relative format to relative format, or 5) A difference value between the first time information and third time information associated with the RAN node 1.

[0096] Format conversion type 1: For format conversion type 1, the second time information is represented by an absolute time value (eg, UTC time), and the RAN node 1 also uses the absolute time format for the first time information.

[0097] The second epoch time (T e2,UTC ) or the second effective time (T v2,UTC At least one of the timestamps (called timestamps or timestamps) is expressed as UTC time, which is an integer in the range from 0 to 549755813887 ms, i.e., an integer number in milliseconds (0..549755813887).

[0098] RAN node 1 receives the first epoch time (T e1,UTC ) or the first effective time (T v1,UTC The method determines that at least one of the timestamps (called timestamps in milliseconds) is represented by UTC time, and that UTC time is an integer in the range of 0 to 549755813887 ms, i.e., an integer number in milliseconds (0..549755813887).

[0099] In detail, the transformation of the two parameters is calculated as follows: T e1,UTC = T e2,UTC + T, T v1,UTC = T v2,UTC However, T is T e2,UTC From T e1,UTC is the eclipsed time duration.

[0100] Format conversion type 2: For format conversion type 2, the received second time information is represented by an absolute time value (e.g., UTC time). The RAN node 1 uses a relative time format based on the reference time of the RAN node 1 (e.g., an uplink time synchronization reference point of the RAN node 1 or an epoch time related to the RAN node 1, such as point 1 or point 2 in FIG. 2A) and the time format (e.g., frame, subframe, and slot numbers).

[0101] A second epoch time associated with RAN node 2 (i.e., T e2,UTC ) or the second effective time (i.e., T v2,UTC ) is expressed as UTC time, which is an integer in the range from 0 to 549755813887 ms, i.e., an integer number in milliseconds (0..549755813887).

[0102] RAN node 1 receives the first epoch time associated with RAN node 2 (i.e., T e1,frame ) or the first valid time (i.e., T v1,frame ), which may be represented by at least one of three integers: a first integer representing a frame number of the second epoch time and ranging from 0 to 1023 (i.e., integer(0..1023)), a second integer representing a subframe number of the second epoch time and ranging from 0 to 9 (i.e., integer(0..9)), and a third integer representing a slot number of the second epoch time and ranging from 0 to 2 μ -1 (i.e., integers (0..2 μ -1)), where μ = 0, 1, 2, 3, 4 correspond to SCS frequencies of 15, 30, 60, 120, and 240 kHz, respectively, for NR, and μ = 1 for LTE.

[0103] In detail, the transformation of the two parameters is calculated as follows: T e1,frame Frame number = Floor [0.1 × (T e2,UTC - T ref,UTC + T - Tref,RN1 )] mod 1024 T e1,frame Subframe number of = Floor (T e2,UTC - T ref,UTC + T - T ref,RN1 ) mod 10 T e1,frame Slot number = Floor [2 μ ×(T e2,UTC - T ref,UTC + T - T ref,RN1 )] mod (2 μ ×10 T v1,frame Frame number = Floor [0.1 × (T v2,UTC - T ref,UTC - T ref,RN1 )] mod 1024 T v1,frame Subframe number of = Floor (T v2,UTC - T ref,UTC - T ref,RN1 ) mod 10 T v1,frame Slot number = Floor [2 μ ×(T v2,UTC - T ref,UTC - T ref,RN1 )] mod (2 μ ×10) however, T is for T e2,UTC From T e1, frame The duration of the eclipse is T ref,UTC is the reference UTC time 00:00:00 on 1 January 1900 in the Gregorian calendar. The value is expressed in milliseconds. T ref,RN1 is the uplink time synchronization reference point of RAN node 1. For NR, μ=0 / 1 / 2 / 3 / 4 correspond to SCS 15 / 30 / 60 / 120 / 240 respectively, and for LTE, μ=1. T e1,frame and / or T v1,framemay include frame, subframe, and slot numbers, frame and subframe numbers, frame numbers only, or other combinations of frame, subframe, and slot numbers, depending on its accuracy requirements.

[0104] Format conversion type 3: For format conversion type 3, the received second time information is represented by a relative time value (e.g., frame, subframe, and slot number) and a reference time of RAN node 2 (e.g., an uplink time synchronization reference point of RAN node 2). RAN node 1 can convert the relative time value into an absolute time value (e.g., UTC time) based on the reference time of RAN node 1 (e.g., an uplink time synchronization reference point of RAN node 1 or an epoch time related to RAN node 1, such as point 1 or point 2 in FIG. 2A) and the time format (e.g., frame, subframe, and slot number).

[0105] A second epoch time associated with RAN node 2 (i.e., T e2,frame ) or the second effective time (i.e., T v2,frame At least one of the integers may be represented by at least one of three integers: a first integer representing a frame number of the second epoch time and ranging from 0 to 1023 (i.e., integer(0..1023)), a second integer representing a subframe number of the second epoch time and ranging from 0 to 9 (i.e., integer(0..9)), and a third integer representing a slot number of the second epoch time and ranging from 0 to 2 μ -1 (i.e., integers (0..2 μ -1)), where μ = 0, 1, 2, 3, 4 correspond to SCS of 15, 30, 60, 120, 240 kHz, respectively, for NR, and μ = 1 for LTE. The uplink time synchronization reference point of RAN node 2 is T ref,RN2 It is.

[0106] RAN node 1 receives a first epoch time (i.e., Te1,UTC ) or the first valid time (i.e., T v1,UTC ) is determined. e1,UTC and T v1,UTC The value of may be represented by an integer having a range from 0 to 549755813887 ms (i.e., Integer(0..549755813887)).

[0107] In detail, the format conversion is as follows. T e2,UTC = T ref,RN2 + (10×T e2,frame frame number) + T e2,frame Subframe number of + (2 -μ ×T e2,frame slot number) + T, T v1,UTC = T ref,RN2 + (10×T v2,frame frame number) + T v1,frame Subframe number of + (2 -μ ×T v2,frame slot number), however, T is for T e2,frame From T e1,UTC is the duration of the eclipse until For NR, μ = 0 / 1 / 2 / 3 / 4 correspond to SCS 15 / 30 / 60 / 120 / 240 kHz, respectively, and for LTE, μ = 1. T e2,frame or T v2,frame may include frame, subframe, and slot numbers, frame and subframe numbers, frame numbers only, or other combinations of frame, subframe, and slot numbers, depending on its accuracy requirements.

[0108] Format conversion type 4: For format conversion type 4, the second time information is represented in a relative time format, and the RAN node 1 converts the relative time value into an absolute time value based on the reference time of the RAN node 1 (e.g., an uplink time synchronization reference point of the RAN node 1 or an epoch time related to the RAN node 1, such as point 1 or point 2 in FIG. 2A) and the time format (e.g., frame, subframe, and slot numbers).

[0109] A second epoch time associated with RAN node 2 (i.e., T e2,frame ) or the second effective time (i.e., T v2,frame At least one of the integers may be represented by at least one of three integers: a first integer representing a frame number of the second epoch time and ranging from 0 to 1023 (i.e., integer(0..1023)), a second integer representing a subframe number of the second epoch time and ranging from 0 to 9 (i.e., integer(0..9)), and a third integer representing a slot number of the second epoch time and ranging from 0 to 2 μ_RN2 -1 (i.e., integers (0..2 μ_RN2 -1)), where μ_RN2=0,1,2,3,4 corresponds to SCS of 15, 30, 60, 120, 240 kHz, respectively, and μ_RN2=1 for LTE. The uplink time synchronization reference point of RAN node 2 is T ref,RN2 It is.

[0110] RAN node 1 receives the first epoch time associated with RAN node 2 (i.e., T e1,frame ) or the first valid time (i.e., T v1,frame ) may be represented by at least one of three integers: a first integer representing a frame number of the second epoch time and ranging from 0 to 1023 (i.e., integer(0..1023)), a second integer representing a subframe number of the second epoch time and ranging from 0 to 9 (i.e., integer(0..9)), and a third integer representing a slot number of the second epoch time and ranging from 0 to 2 μ_RN1 -1 (i.e., integers (0..2μ_RN1 -1)), where μ_RN1=0, 1, 2, 3, 4 correspond to SCS of 15, 30, 60, 120, 240 kHz, respectively, and μ_RN1=1 for LTE. The uplink time synchronization reference point of RAN node 1 is T ref,RN1 It is.

[0111] In detail, the format conversion is as follows. T e1,frame Frame number = Floor {0.1×[T ref,RN2 +(10×T e2,frame frame number) + T e2,frame Subframe number of + (2 -μ_RN2 ×T e2,frame slot number) + T - T ref,RN1 ]} mod 1024, T e1,frame Frame number = Floor [T ref,RN2 + (10×T e2,frame frame number) + T e2,frame Subframe number of + (2 -μ_RN2 ×T e2,frame slot number) + T - T ref,RN1 ] mod 10, T e1,frame Slot number = Floor {2 μ ×[T ref,RN2 +(10×T e2,frame frame number) + T e2,frame Subframe number of +(2 -μ_RN2 ×T e2,frame slot number) + T - T ref,RN1 ]} mod (2 μ_RN1 ×10), T v1,frame Frame number = Floor {0.1 × [T ref,RN2 +(10×T v2,frame (frame number) + T v2,frame Subframe number of +(2 -μ_RN2 ×T v2,frame slot number) - T ref,RN1 ]} mod 1024, T v1,frameFrame number = Floor [T ref,RN2 + (10×T ev1,frame frame number) + T v1,frame Subframe number of + (2 -μ_RN2 ×T v1,frame slot number) - T ref,RN1 ] mod 10, T v1,frame Slot number = Floor {2 μ ×[T ref,RN2 +(10×T v1,frame frame number) + T v1,frame Subframe number of +(2 -μ_RN2 ×T v1,frame slot number) - T ref,RN1 ]} mod (2 μ_RN1 ×10). however, T is for T e1,frame to the uplink time synchronization reference time point of RAN node 1, i.e., T ref,RN1 is the duration until T ref,RN1 is the uplink time synchronization reference point of RAN node 1, μ_RN1 and μ_RN2 may be the same or different depending on the air interface protocol used, T e1,frame , T v1,frame , T e2,frame , or T v2,frame may include frame, subframe, and slot numbers, frame and subframe numbers, frame numbers only, or other combinations of frame, subframe, and slot numbers, depending on its accuracy requirements.

[0112] Format conversion type 5: Similar to the second time information related to RAN node 2, RAN node 1 includes third time information, which may include at least one of the following: 1) A third epoch time associated with the ephemeris of RAN node 1 or the common TA; 2) a third validity time associated with the ephemeris of RAN node 1 or the common TA, or 3) A third reference time point for a third epoch time and / or a third validity time associated with the RAN node 1.

[0113] For format conversion type 5, the RAN node 1 provides the first time information related to the RAN node 2 together with the third time information related to the RAN node 1, and the first time information related to the RAN node 2 is provided to the UE by a difference value compared with the third information related to the RAN node 1.

[0114] The epoch time associated with RAN node 1 (i.e., T e3,frame ) and effective time (i.e., T v3,frame ) is represented by a frame and subframe number, which may be represented by at least one of two integers. As specified by 3GPP documents, the first frame number is an integer in the range from 0 to 1023 (i.e., integer(0..1023)) and the second subframe number is an integer in the range from 0 to 9 (i.e., integer(0..9)). The uplink time synchronization reference point of RAN node 1 is T ref,RN1 The RAN node 1 determines that at least one of the first epoch time or the first validity time associated with the RAN node 2 is equal to or greater than T e3,frame and T v3,frame The delta value T in milliseconds compared to e1,diff or T v1,diff The method determines that the metric is represented by at least one of:

[0115] In detail, the difference value T e1,diff or T v1,diff At least one of the following is calculated:

[0116] When the first time information and the third time information are expressed in UTC format, the format conversion is as follows: T e1,diff = T e1,UTC- [T ref,RN1 +(10×T e3,frame (frame number) + T e3,frame subframe number], T v1,diff = T v1,UTC - [T ref,RN1 +(10×T v3,frame (frame number) + T v3,frame [subframe number of the

[0117] When the first time information and the third time information are expressed in a relative format, the format conversion is as follows: T e1,diff = [(10×T e1,frame frame number) + T e1,frame Subframe number of +(2 -μ ×T e1,frame slot number)]-[(10×T e3,frame frame number) + T e3,frame subframe number], T v1,diff = [(10×T v1,frame frame number) + T v1,frame Subframe number of +(2 -μ ×T v1,frame slot number)]-[(1×T v3,frame frame number) + T v3,frame [subframe number of the however, T ref,RN1 is the uplink time synchronization reference point of RAN node 1, For NR, μ = 0 / 1 / 2 / 3 / 4 correspond to SCS 15 / 30 / 60 / 120 / 240 kHz, respectively, and for LTE, μ = 1. μ_RN1 and μ_RN2 may be the same or different depending on the air interface protocol used, T e1,frame and / or T v1,frameis the first epoch time and / or the first validity time associated with the RAN node 2, and may include frame, subframe, and slot numbers, frame and subframe numbers, frame number only, or other combinations of frame, subframe, and slot numbers depending on its accuracy requirements.

[0118] In some other scenarios, the epoch time (and / or validity time) of RAN node 2 shares the epoch time (and / or validity time) of RAN node 1, i.e., they have the same values ​​and parameters. In other words, the first epoch time (and / or the first validity time) of RAN node 2 is identical to the third epoch time (and / or the third validity time) of RAN node 1, respectively. In this case, the first epoch time (and / or the first validity time) of RAN node 2 may not be set to default in the first time information transmitted to the UE.

[0119] After determining the first time information associated with RAN node 2, in operation 504, RAN node 1 transmits the first time information to the UE via SI broadcast, on-demand SI, dedicated signaling, or other message.

[0120] The first time information relating to the RAN node 2 may include at least one of the following: 1) The first epoch time associated with the ephemeris, common TA, or feeder link propagation delay of RAN node 2. If it is absent or set to default, the first epoch time is the same as the third epoch time associated with RAN node 1. 2) A first validity time associated with the ephemeris, common TA, or feeder link propagation delay of RAN node 2. If it is absent or set to default, the first validity time is the same as the third validity time associated with RAN node 1. 3) A first reference time point for at least one of the first epoch time or the first validity time associated with RAN node 2. If it is absent or set to a default, the first reference time point for at least one of the first epoch time or the first validity time associated with RAN node 2 is the same as the third reference time point for at least one of the third epoch time or the third validity time associated with RAN node 1. 4) An indication that the first epoch time or validity time associated with RAN node 2 is shared by the RAN node ephemeris, the common TA, or the feeder link propagation delay. 5) An indication that the first epoch time or validity time associated with RAN node 2 is the same as that associated with RAN node 1; or 6) An indication that the first reference point in time associated with RAN node 2 is the same as that associated with RAN node 1.

[0121] In some embodiments, the first epoch time may be represented in a UTC time format, alternatively, the first epoch time may be represented in a relative format or may be a relative time to a reference point in time, for example, represented by frame, subframe, and slot numbers, or milliseconds. When indicated in a SIB other than SIB1, as shown in FIG. 2B, the epoch time may be the end of the SI window in which the SI message is transmitted.

[0122] In some embodiments, the first valid time may be in the form of an absolute time, e.g., represented by a UTC time format. Until the first valid time expires, the associated ephemeris, common TA, or feeder link propagation delay is considered valid. Alternatively, the first valid time may be in the form of a relative duration to a reference time point, e.g., represented by a frame, subframe, and slot number, or milliseconds, during which the associated ephemeris, common TA, or feeder link propagation delay value is considered valid.

[0123] In some embodiments, if the serving BS and the satellite are in different locations, the third reference time point may be between the serving BS and the satellite, or may be at the serving BS, the satellite, or the UE, or may be at an epoch time related to the serving BS. For example, it may be an uplink time synchronization reference point of the RAN node 1, such as point 1 in FIG. 2A, or may be at the serving BS, the satellite, or the UE, or may be at an epoch time related to the serving BS (i.e., point 2 in FIG. 2A). If the serving BS and the satellite are in the same location, the location between the serving BS and the satellite, the serving BS, and the satellite refer to the same location.

[0124] In operation 505, based on the received first time information related to the RAN node 2, the UE determines a time-related status of the RAN node 2.

[0125] The time-related status includes at least two parts: a spatial status and a temporal status.

[0126] The determination of the spatial status may include at least one of the following:

[0127] The UE may then assign a parameter value (e.g., ephemeris) of the RAN node 2 associated with the received first time information to the first epoch time T e1 The value at is determined.

[0128] The UE may store a parameter value (e.g., ephemeris) of the RAN node 2 associated with the received first time information until the first validity time or until the first epoch time T e1 The second validity duration is determined to be valid for a second validity duration beginning at .

[0129] The UE determines the target time T based on the coordinates received in the time information and its epoch time as follows: targetThe coordinates of RAN node 2 in (i.e., (X target , Y target , Z target )) to calculate X target = X received +ΔX received ×(T target -T e1 ), Y target = Y received +ΔY received ×(T target -T e1 ), and Z target = Z received +ΔZ received ×(T target -T e1 ), However, (X received , Y received , Z received ) and (ΔX received , ΔY received , ΔZ received ) are the first epoch time T e1 are the coordinates and velocity of RAN node 2 at

[0130] The UE determines the target time T based on the orbital position and its epoch time received in the time information. target Calculate the orbital position of RAN node 2 at target time T target The orbital position of RAN node 2 at is calculated as follows: M target = M received + (Gm / α 3 )^(1 / 2)×(T target -T e1 ) however, M received is the first epoch time T e1 is the orbital position of RAN node 2 in α is the semi-major axis in the RAN node 2 ephemeris, G is the gravitational constant, m is the mass of the Earth, Gm ≒ 398601 km 3 / s 3 It is.

[0131] The determination of the temporal status may include at least one of the following:

[0132] The UE may determine parameter values ​​of the RAN node 2 associated with the received first time information (eg, common TA, feeder link propagation delay) as values ​​at the first epoch time.

[0133] The UE determines parameter values ​​(e.g., common TA, feeder link propagation delay) of the RAN node 2 associated with the received first time information as valid until the first validity time or during a first validity duration starting at the first epoch time.

[0134] The UE may start a validity timer for the parameter value in the received first time information upon receipt. The length of the validity timer may be: L ValidityTimer = T v1,UTC -T current,UTC L ValidityTimer = T v1,frame -(T current,frame -T e2,frame ) However, T current,UTC and T current,frame are the current time (i.e., the time of receipt) in UTC or relative format, respectively.

[0135] In some embodiments, the UE may discard the above parameter values ​​as well as any calculation results in the received first time information after the first validity time or after expiry of a first validity timer included in the first time information related to the RAN node 2.

[0136] In some embodiments, the UE may request further time information related to the RAN node 2 after the first validity time or after expiration of the first validity timer.

[0137] Target Time Ttarget The common TA for RAN node 2 in is calculated as follows: T.A. common, target = TA common, received +ΔTA common, received ×(T target -T e1 ) However, T.A. common,received and ΔTA common,received are the first epoch time T e1 are the common TA values ​​and change rates of RAN node 2 in

[0138] Target Time T target The feeder link delay for RAN node 2 at is calculated as follows: FL delay, target = FL delay, received +ΔFL delay, received ×(T target -T e1 ) However, FL delay, received and ΔF delay, received are the first epoch time T e1 RAN node 2's feeder link delay value and rate of change at

[0139] Propagation delay SL between the UE and RAN node 2 delay, target is calculated as follows: SL delay, target = [(X target -X UE ) 2 + (Y target -Y UE ) 2 + (Z target -Z UE ) 2 ] 1 / 2 / c However, (X UE , Y UE , Z UE ) is the position of the UE and c is the speed of light.

[0140] Alternatively, the propagation delay may be calculated as follows: SL delay, target = [α×(1-e2 sin 2 M target ) 1 / 2 -R Earth ] / c where c is the speed of light and R Earth is the mean radius of the Earth.

[0141] With the above solution, the UE can obtain the time information of the RAN node 2, which may be a neighboring RAN node, or a nearby RAN node, or any other RAN node.

[0142] 6 illustrates a block diagram of an example apparatus 600 according to some embodiments of the present disclosure. As shown in FIG. 6, the apparatus 600 may include at least one processor 604 and at least one transceiver 602 coupled to the processor 604. The apparatus 600 may be a UE or a BS.

[0143] In this figure, elements such as at least one transceiver 602 and processor 604 are described in the singular, but the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the transceiver 602 may be split into two devices, such as a receiving circuit and a transmitting circuit. In some embodiments of the present disclosure, the apparatus 600 may further include an input device, a memory, and / or other components.

[0144] In some embodiments of the present disclosure, the apparatus 600 may be a UE. The transceiver 602 and the processor 604 may interact with each other to perform operations for the UE, such as those described above in FIGS.

[0145] In some embodiments of the present disclosure, the apparatus 600 may be a BS. The transceiver 602 and the processor 604 may interact with each other to perform operations for the BS, such as those described above in FIGS.

[0146] In some embodiments of the present disclosure, the apparatus 600 may further include at least one non-transitory computer-readable medium. For example, in some embodiments of the present disclosure, the non-transitory computer-readable storage medium may have stored thereon computer-executable instructions for causing the processor 604 to perform the methods for the UE described above. For example, the computer-executable instructions, when executed, cause the processor 604, which interacts with the transceiver 602, to perform the operations for the UE described above in FIGS. 1-5.

[0147] In some embodiments of the present disclosure, the apparatus 600 may further include at least one non-transitory computer-readable medium. For example, in some embodiments of the present disclosure, the non-transitory computer-readable storage medium may have computer-executable instructions stored thereon for causing the processor 604 to perform the methods for the BS described above. For example, the computer-executable instructions, when executed, cause the processor 604 interacting with the transceiver 602 to perform the operations for the BS described above in FIGS. 1-5.

[0148] The methods of the present disclosure may be implemented on a programmed processor. However, the controllers, flowcharts, and modules may also be implemented in hardware electronic or logic circuits such as general purpose or special purpose computers, programmed microprocessors or microcontrollers, peripheral integrated circuit elements, integrated circuits, discrete element circuits, programmable logic devices, etc. In general, any device having a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

[0149] Although the present disclosure has been described with its specific embodiments, it is apparent that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the present embodiment may be replaced, added, or substituted in other embodiments. Also, not all elements shown in each figure are necessary for the operation of the disclosed embodiments. For example, a person skilled in the art of the disclosed embodiments will be able to make and use the teachings of the present disclosure by simply using the elements of the independent claims. Thus, the embodiments of the present disclosure shown herein are intended to be illustrative, not limiting. Various modifications may be made without departing from the spirit and scope of the present disclosure.

[0150] In this disclosure, relational terms such as "first", "second", etc. may be used merely to distinguish one entity or action from another entity or action, and do not necessarily require or imply an actual such relationship or order between such entities or actions. The terms "comprise", "comprising", or other variations thereof, are intended to include non-exclusive inclusions, and a process, method, article, or apparatus that includes a list of elements may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "a", "an", etc., does not preclude the presence of additional identical elements in a process, method, article, or apparatus that includes this element, unless further constrained. Also, the term "another" is defined as at least a second or additional. As used herein, the terms "including", "having", etc. are defined as "comprising". [Explanation of symbols]

[0151] 102 satellite 201 User Equipment (UE) 202 Satellite 203BS 301UE 302 satellite 303BS 401UE 402 satellite 403BS 4001 Time information 4002 Time information 600 equipment 602 Transceiver 604 Processor

Claims

1. 1. A Radio Access Network (RAN) node, comprising: A transceiver; Processor and wherein the processor: determining first time information associated with a neighboring RAN node of the RAN node; transmitting the first time information to a user equipment (UE); and the first time information is a first epoch time associated with the neighboring RAN node; or a first validity time associated with the neighboring RAN node; RAN node, comprising at least one of:

2. The first time information is determined based on second time information of the neighboring RAN node, and the second time information is a second epoch time associated with the neighboring RAN node; or a second validity time associated with the neighboring RAN node; 2. The RAN node of claim 1, comprising at least one of:

3. 3. The RAN node of claim 2, wherein the second time information is pre-stored in the RAN node or received from the neighboring RAN node in response to a request from the RAN node to the neighboring RAN node.

4. The request, An indication requesting a part of the second time information or all of the second time information; the identity of the neighboring RAN node; or Preferred format of said second time information 4. The RAN node of claim 3, comprising at least one of:

5. The first time information is represented in a first format, the second time information is represented in a second format, and the processor: Converting the second time information in the second format into the first time information in the first format The RAN node of claim 2, further configured:

6. At least one of the first epoch time or the first validity time is: the ephemeris of the neighboring RAN nodes; the common Timing Advance (TA) of said neighbouring RAN nodes, or Feeder link propagation delay of the neighboring RAN nodes 2. The RAN node of claim 1, wherein the RAN node is associated with at least one of:

7. 2. The RAN node of claim 1, wherein the first time information further comprises a first reference time point for at least one of the first epoch time or the first validity time.

8. 2. The RAN node of claim 1, wherein the first time information is transmitted to the UE by a system information (SI) broadcast, an on-demand SI, or a dedicated signaling.

9. The first time information is the first epoch time has the same value as a third epoch time associated with the RAN node, the third epoch time being associated with at least one of an ephemeris of the RAN node or a common TA of the RAN node; or the first validity time has the same value as a third validity time associated with the RAN node, the third validity time being associated with at least one of an ephemeris of the RAN node or a common TA of the RAN node; 2. The RAN node of claim 1, wherein the RAN node is configured to:

10. A user equipment (UE), A transceiver; Processor and wherein the processor: receiving, from a Radio Access Network (RAN) node, first time information associated with a neighboring RAN node of the RAN node; determining a time-related status of the neighboring RAN nodes based on the first time information; and and the first time information is a first epoch time associated with the neighboring RAN node; or a first validity time associated with the neighboring RAN node; The UE includes at least one of:

11. At least one of the first epoch time or the first validity time is: the ephemeris of the neighboring RAN nodes; the common Timing Advance (TA) of said neighbouring RAN nodes, or Feeder link propagation delay of the neighboring RAN nodes The UE of claim 10, wherein the UE is associated with at least one of the following:

12. The UE of claim 10, wherein the first time information further includes a first reference time point for at least one of the first epoch time or the first validity time.

13. The UE of claim 10, wherein the first time information is received by a system information (SI) broadcast, an on-demand SI, or a dedicated signaling.

14. The time related status of the neighboring RAN nodes, at least one of an ephemeris, a common TA, or a feeder link propagation delay at the first epoch time; At least one of the ephemeris, the common TA, or the feeder link propagation delay being valid; At least one of the ephemeris, the common TA, or the feeder link propagation delay at a given time; the coordinates of the neighboring RAN nodes at a given time; the orbital positions of the neighboring RAN nodes at a given time; a neighboring RAN node parameter value validity timer that is started when the first time information is received; the length of the validity timer from the time of receipt to the first validity time; the first epoch time has the same value as a third epoch time associated with the RAN node, the third epoch time being associated with at least one of an ephemeris of the RAN node or a common TA of the RAN node; or the first validity time has the same value as a third validity time associated with the RAN node, the third validity time being associated with at least one of an ephemeris of the RAN node or a common TA of the RAN node; The UE of claim 10, comprising at least one of:

15. If the first time information includes the first valid time, the processor: discarding the received first time information associated with the neighboring RAN node upon expiration of the first validity period; discarding the determined time-related status based on the first time information when the first validity time expires; the UE assumes that it has lost uplink synchronization to the neighboring RAN node; or and upon expiration of the first validity period, requesting an update of the first time information associated with the neighboring RAN node. The UE of claim 10, further configured to perform at least one of the following:

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