Timing adjustment in non-terrestrial wireless communications

Abstract

Methods, systems, and devices are described for wireless communication in which a UE can communicate with a satellite and a base station or gateway in a non-terrestrial network (NTN). Due to the large distances between the transmitting and receiving devices in an NTN, timing adjustment for a communication link that accounts for propagation delay via the satellite can include the propagation delay between the UE and the satellite, the propagation delay between the base station and the satellite, and a change in the propagation delay due to movement of the satellite. According to various techniques discussed herein, when determining an uplink timing for an uplink communication via the satellite, the UE can account for the change in the propagation delay in addition to the determined propagation delay.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This Patent Application claims priority to U.S. Patent Application No. 17 / 188,943 by Shrestha et al., entitled “TIMING ADJUSTMENT IN NON-TERRESTRIAL WIRELESS COMMUNICATIONS” filed March 1, 2021, and U.S. Provisional Patent Application No. 62 / 987,216 by Shrestha et al., entitled “TIMING ADJUSTMENT IN NON-TERRESTRIAL WIRELESS COMMUNICATIONS” filed March 9, 2020, each of which is assigned to the assignee hereof and hereby expressly incorporated by reference herein in its entirety. TECHNICAL FIELD

[0003] The following relates generally to wireless communication, and more specifically to timing adjustment in non-terrestrial wireless communications.

[0004] BACKGROUND

[0005] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple- access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which can be referred to as New Radio (NR) systems. These systems can employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system can include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which can be otherwise known as user equipment (UE).

[0006] In some situations, such as when a gateway or base station and a UE are part of a non-terrestrial network (NTN), there may be a large distance between the UE and the UE's serving node. Due to the distance between the UE and the gateway in such situations, there may be a relatively long round-trip delay or propagation delay in message transmission between the UE and the gateway (e.g., relative to a terrestrial network). Therefore, efficient techniques for managing communications with such relatively long round-trip or propagation delays are desirable for such systems.

[0007] Overview

[0008] The described technology relates to improved methods, systems, devices and apparatuses for supporting timing adjustments in non-terrestrial wireless communications. According to various aspects, timing adjustments that account for propagation delay in a non-terrestrial network (NTN) may include propagation delay between a user equipment (UE) and a satellite, and changes in propagation delay due to movement of the satellite. For example, due to the relative high speed of the satellite relative to the UE or a serving gateway (e.g., which may be an example of a base station) in communication with the UE via the satellite, the round-trip delay (RTD) (e.g., used to determine the timing advance used to align uplink communications from the UE with a receiving device timing reference) can change relatively quickly. According to the various techniques discussed herein, when determining uplink timing for uplink communications via a satellite, the UE may account for changes in propagation delay in addition to the determined propagation delay.

[0009] In some cases, the gateway may configure the UE to use the gateway timing reference, and the UE may therefore adjust the uplink transmission timing so that the uplink transmission from the UE to the gateway arrives at the gateway with a time alignment corresponding to the frame boundary measured by the gateway timing reference. In some such cases, the UE may determine the RTD associated with communication with the gateway, which takes into account one or more of the propagation delay from the UE to the satellite, the propagation delay variation from the UE to the satellite, the propagation delay from the satellite to the gateway, or the propagation delay variation from the satellite to the gateway. In some cases, the gateway may provide signaling to the UE that includes RTD and RTD variation information that can be used to determine uplink timing. In other cases, the UE may determine one or more of the RTD or RTD variation information. In some cases, the gateway may configure the UE to use the satellite timing reference, and the UE may therefore adjust the uplink transmission timing so that the uplink transmission from the UE to the satellite arrives at the satellite with a time alignment corresponding to the frame boundary measured by the satellite timing reference.

[0010] A method of wireless communication at a UE is described. The method may include: identifying a propagation delay for communication between the UE and a base station via a satellite based on round-trip delay information received from a network; determining uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and a propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmitting the uplink communication to the base station via the satellite based on the uplink timing.

[0011] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: identify a propagation delay for communication between the UE and a base station via a satellite based on round-trip delay information received from a network; determine uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmit the uplink communication to the base station via the satellite based on the uplink timing.

[0012] Another apparatus for wireless communications at a UE is described. The apparatus may include means for: identifying a propagation delay for communications between the UE and a base station via a satellite based on round-trip delay information received from a network; determining uplink timing for initiating uplink communications to the base station via the satellite based on the propagation delay and a propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmitting the uplink communications to the base station via the satellite based on the uplink timing.

[0013] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: identify a propagation delay for communication between the UE and a base station via a satellite based on round-trip delay information received from a network; determine uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmit the uplink communication to the base station via the satellite based on the uplink timing.

[0014] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for determining a first portion of a propagation delay and a first propagation delay variation for a UE-to-satellite link, determining a second portion of a propagation delay and a second propagation delay variation for a satellite-to-base station link, and wherein the propagation delay for communications between the UE and the base station can be based on one or more of the first portion of the propagation delay, the first propagation delay variation, the second portion of the propagation delay, or the second propagation delay variation. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for receiving configuration information indicating whether uplink timing is based on a UE-to-satellite propagation delay or a UE-to-gateway propagation delay. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information can be provided in a system information broadcast transmission or in UE-specific signaling.

[0015] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for, or instructions for receiving paging information that a round-trip delay information is to be updated. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the paging information can be provided in an indication bit in a downlink control information paging indication, in a direct indication in downlink control information, or in a paging indication scrambled with a radio network temporary identifier (RNTI) associated with a round-trip delay information update.

[0016] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information indicates that uplink timing is based on a UE-to-base station propagation delay, and wherein the configuration information further provides a round-trip delay offset associated with the base station and the satellite and a round-trip delay variation associated with the base station and the satellite. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information indicates that uplink timing is based on a UE-to-satellite propagation delay, and wherein the uplink timing is determined based only on the UE-to-satellite propagation delay. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information can be received in a master information block (MIB).

[0017] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means for performing, or instructions for causing an apparatus to: identify a validity time associated with the round-trip delay information, and monitor for updated round-trip delay information in response to an expiration of the validity time. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the validity time can be based on a predefined modification period or based on receiving configuration information that configures the modification period, and where the UE monitors for the updated round-trip delay information once per modification period. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the validity time starts when acquiring a system information block (SIB) containing the round-trip delay information, and where monitoring for the updated round-trip delay information includes acquiring another instance of the SIB. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the round-trip delay information includes an initial value for a propagation delay for an initial access procedure, and where the propagation delay change is determined based on a duration in which a plurality of propagation delays are determined after the initial access procedure. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the round-trip delay information includes a satellite-to-base station propagation delay, and where the UE determines a UE-to-satellite propagation delay, and where the propagation delay change is determined based on a duration for determining the plurality of propagation delays.

[0018] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the round-trip delay information further includes a UE-to-satellite propagation delay. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a midpoint of a transmission beam coverage area of a transmission beam used for communications with the UE can be considered a location of the UE for the UE-to-satellite propagation delay. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the round-trip delay information includes a base station-to-UE propagation delay for an initial access procedure, and where a propagation delay change is determined after the initial access procedure.

[0019] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the identification may further include operations, features, means, or instructions for the following actions: receiving a broadcast transmission including round-trip delay information, and wherein the broadcast transmission is broadcast periodically with a first periodicity. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the round-trip delay information includes propagation delay and propagation delay variation. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the propagation delay is transmitted with a first periodicity, and the propagation delay variation is transmitted with a second periodicity that may be different from the first periodicity. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the first periodicity may be a first predefined fixed periodicity, or may be configured in signaling transmitted to the UE, and wherein the second periodicity may be a second predefined fixed periodicity, or may be configured in signaling transmitted to the UE. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the propagation delay may be provided in the broadcast signaling, and the propagation delay variation may be provided in dedicated signaling to the UE.

[0020] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for determining one or more of propagation delays or propagation delay variations based on one or more of information from a global navigation satellite system (GNSS) component at the UE, ephemeris information associated with a satellite, information provided by a base station, or any combination thereof.

[0021] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the round-trip delay information includes an indication of a propagation delay and may be periodically provided by a base station, and wherein a propagation delay variation may be determined based on a difference between two or more instances of the propagation delay. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the propagation delay variation may be determined based on a difference between two instances of the propagation delay and a time difference in receiving the two instances of the propagation delay.

[0022] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, identification may include operations, features, means, or instructions for the following actions: receiving an indication of a base station location in round-trip delay information, and determining one or more of a propagation delay or a propagation delay variation based on the base station location, the UE location, and the satellite location. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the base station location may be provided in radio resource control signaling when the UE is in connected mode with the base station. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the base station location may be a virtual geographic location that allows determination of a propagation delay variation and is provided in dedicated signaling or broadcast signaling to the UE. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, uplink timing for initiating uplink communication to the base station is based on the UE-to-satellite propagation delay and the UE-to-satellite propagation delay variation, regardless of the satellite-to-base station propagation delay or the satellite-to-base station propagation delay variability.

[0023] A method for wireless communication at a base station is described. The method may include identifying round-trip delay information associated with a propagation delay for communication with at least a first UE via a satellite; determining, based on the round-trip delay information, configuration information that instructs the first UE to identify a propagation delay and a propagation delay variation for uplink communication via the satellite to the base station based on a satellite timing reference or a base station timing reference, wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmitting the configuration information to at least the first UE.

[0024] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: identify round-trip delay information associated with a propagation delay for communication with at least a first UE via a satellite; determine, based on the round-trip delay information, configuration information instructing the first UE to identify a propagation delay and a propagation delay variation for uplink communication via the satellite to the base station based on a satellite timing reference or a base station timing reference, wherein the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station; and transmit the configuration information to at least the first UE.

[0025] Another apparatus for wireless communication at a base station is described. The apparatus can include means for identifying round-trip delay information associated with a propagation delay for communications with at least a first UE via a satellite, determining configuration information based on the round-trip delay information, the configuration information indicating that the first UE is to identify a propagation delay and a propagation delay variation for uplink communications to the base station via the satellite based on a satellite timing reference or a base station timing reference, where the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station, and transmitting the configuration information to at least the first UE.

[0026] A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code can include instructions executable by a processor to identify round-trip delay information associated with a propagation delay for communications with at least a first UE via a satellite based on a satellite timing reference or a base station timing reference, determine configuration information based on the round-trip delay information, the configuration information indicating that the first UE is to identify a propagation delay and a propagation delay variation for uplink communications to the base station via the satellite, where the propagation delay variation is based on movement of the satellite relative to one or more of the UE or the base station, and transmit the configuration information to at least the first UE.

[0027] In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information includes a variable that indicates, based at least in part on a value of the variable, whether uplink timing is based on the satellite timing reference and a propagation delay of the UE to the satellite or the base station timing reference and a propagation delay of the UE to the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information can be transmitted in a system information broadcast transmission from the base station or in UE-specific signaling to the first UE.

[0028] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein can further include operations, features, means, or instructions for transmitting, to at least the first UE, a paging message indicating that the first UE is to update the round-trip delay information. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the paging message to update the round-trip delay information can be provided in an indication bit in a downlink control information paging indication, in a direct indication in downlink control information, or in a paging indication scrambled with a radio network temporary identifier (RNTI) associated with a round-trip delay information update.

[0029] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the configuration information indicates that the uplink timing may be based on a propagation delay from the UE to the base station, and wherein the configuration information further provides a round-trip delay offset associated with the base station and the satellite, and a round-trip delay variation associated with the base station and the satellite. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the configuration information indicates that the uplink timing may be based on a propagation delay from the UE to the satellite, and wherein the uplink timing may be determined based solely on the propagation delay from the UE to the satellite. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the configuration information may be transmitted in a master information block (MIB).

[0030] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for periodically transmitting instances of configuration information having updated round-trip delay information. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the periodicity of transmitting instances of configuration information having updated round-trip delay information may be based on a predefined modification period or a configured modification period indicated in the configuration information. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the round-trip delay information includes an initial value of the propagation delay for an initial access procedure, and wherein a propagation delay change may be determined after the initial access procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1

[0014] An example of a system for wireless communications supporting timing adjustment in non-terrestrial wireless communications in accordance with aspects of the present disclosure is illustrated.

[0033] Figure 2

[0014] An example of a wireless communication system supporting timing adjustment in non-terrestrial wireless communications in accordance with aspects of the present disclosure is illustrated.

[0034] Figure 3 Examples of frame timing supporting timing adjustment in non-terrestrial wireless communications are illustrated in accordance with aspects of the present disclosure.

[0035] Figure 4 An example of a process flow for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated.

[0036] Figure 5 An example of a process flow for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated.

[0037] Figure 6 and 7A block diagram of a device that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0038] Figure 8 A block diagram of a communications manager that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0039] Figure 9 A diagram of a system including a device that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0040] Figure 10 And 11 A block diagram of a device that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0041] Figure 12 A block diagram of a communications manager that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0042] Figure 13 A diagram of a system including a device that supports timing adjustment in non-terrestrial wireless communications is shown, in accordance with aspects of the present disclosure.

[0043] Figures 14 to 18 A flow diagram illustrating a method that supports timing adjustment in non-terrestrial wireless communications in accordance with aspects of the present disclosure is shown.

[0044] DETAILED DESCRIPTION

[0045] A non-terrestrial network (sometimes referred to as an NTN) can provide coverage by using high-altitude vehicles between user terminals and gateways or base stations (e.g., next generation Node Bs or giga-Node Bs (which can be referred to as gNBs, also referred to as access stations or access gateways)). For example, a gateway can transmit data to a satellite, which can then be relayed to a user terminal, and vice versa. In some examples, the high-altitude vehicles can be base stations. A user terminal can be any device capable of transmitting signals to a satellite. Examples of user terminals can include user equipment (UE), relay equipment configured to relay signals between a satellite and a user terminal, or a combination thereof. An NTN can involve using high-altitude platform stations (HAPS) and / or satellites to provide coverage for terrestrial base stations and UEs. The terms HAPS and satellite are used interchangeably herein to refer to a remote NTN device that can provide coverage for one or more other high-altitude or terrestrial devices. Likewise, the terms gateway and base station are used interchangeably herein to refer to a network node that serves UEs and provides network access to the UEs.

[0046] The gateway and the satellite can be thousands of kilometers apart, and it can take some time for electromagnetic waves to propagate between the gateway and the satellite and between the satellite and the user terminal. Thus, the propagation delay for non-terrestrial networks can be many orders of magnitude larger than the propagation delay for terrestrial networks. As such, the round-trip delay (sometimes referred to as RTD) associated with a signal can also be many orders of magnitude larger for non-terrestrial networks than for terrestrial networks. Further, due to the high mobility of high-altitude vehicles, such as non-geostationary satellites, communication with non-geostationary satellites can result in a large and time-varying round-trip delay. Variations in the round-trip delay can result in a user terminal experiencing variations in uplink timing and frequency synchronization with a satellite. As the demand for communication efficiency increases, it can be desirable for a wireless communication system to support techniques for estimating and determining uplink timing that account for the round-trip delay and variations in the round-trip delay.

[0047] As described herein, a UE, a gateway, and a satellite can support estimating a propagation delay and a propagation delay variation for determining timing for uplink transmissions from the UE to the gateway via the satellite. In some cases, the UE can determine the uplink timing such that the uplink transmissions from the UE to the gateway arrive at the gateway in a time-synchronized manner. The UE can apply a timing advance based on the estimated propagation delay and the propagation delay variation between the UE and the satellite, between the satellite and the gateway, or any combination thereof to determine the uplink timing. In some cases, the propagation delay and the propagation delay variation can be determined based on a gateway timing reference (e.g., a base station timing reference) or based on a satellite timing reference. In some cases, a serving gateway can configure the UE to use one of the gateway or satellite timing references. In some cases, the serving gateway can provide information related to a round-trip delay, a variation in the round-trip delay, or both to assist the UE in determining the uplink timing.

[0048] Particular aspects of the subject matter described herein can be implemented to realize one or more of the following potential advantages. The described techniques can support improvements in estimating timing offsets related to communications between high-altitude vehicles (e.g., satellites or other non-ground-based equipment), user terminals, and gateways or base stations in non-terrestrial networks, among other advantages. Thus, the supported techniques can include features for efficient non-terrestrial communications. The described techniques can also support increased spectral efficiency, and in some examples, can enable higher mobility support for user terminals in non-terrestrial networks as compared to terrestrial networks, among other benefits.

[0049] Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are also illustrated by and described in connection with timing diagrams and process flowcharts. Aspects of the disclosure are further illustrated and described by and in connection with apparatus diagrams, system diagrams, and flowcharts related to timing adjustment in non-terrestrial wireless communications.

[0050] Figure 1 An example of a wireless communication system 100 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0051] Base stations 105 may be dispersed throughout a geographic area to form wireless communication system 100 and may be different forms of devices or devices with different capabilities. Base stations 105 and UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which UEs 115 and base stations 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographic area over which base stations 105 and UEs 115 may support signal communication according to one or more radio access technologies.

[0052] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 1 1. The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relays, integrated access and backhaul (IAB) nodes, or other network equipment), such as Figure 1 As shown in .

[0053] Each base station 105 can communicate with the core network 130, or with each other, or both. For example, the base station 105 can interface with the core network 130 via one or more backhaul links (e.g., via S1, N2, N3, or other interfaces). The base stations 105 can communicate with each other directly (e.g., directly between the base stations 105), indirectly (e.g., via the core network 130), or both directly and indirectly over the backhaul links (e.g., via X2, Xn, or other interfaces). In some examples, the backhaul links can be or include one or more wireless links.

[0054] One or more of the base stations 105 described herein can include or can be referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or giga-NodeB (either of which can be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0055] A UE 115 can include or can be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” can also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 can also include or can be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 can include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which can be implemented in various objects such as appliances or vehicles, meters or instruments, among other examples.

[0056] A UE 115 described herein can be able to communicate with various types of devices, such as other UEs 115 that can sometimes act as relays or can be stationary devices such as base stations 105, and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1. Figure 1

[0057] The UEs 115 and the base stations 105 can wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” can refer to a set of radio frequency spectrum resources with a defined physical layer structure for supporting communication links 125. For example, a carrier used for a communication link 125 can include a portion of the radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel can carry acquisition signaling (e.g., synchronization signals, system information), control signaling, user data, or other signaling. The wireless communications system 100 can support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation can be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

[0058] ​The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the code rate of the modulation scheme, or both). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further improve the data rate or data integrity of communications with UE 115.

[0059] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, which can be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported discrete Fourier transform (DFT) size may be indicated. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0060] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of code element periods (e.g., depending on the length of the cyclic prefix added before each code element period). In some wireless communication systems 100, a time slot may be further divided into a plurality of mini-time slots containing one or more code elements. Excluding the cyclic prefix, each code element period may contain one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating band.

[0061] A subframe, a slot, a mini-slot, or a symbol can be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and can be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., number of symbol periods in a TTI) can be variable. Wireless communications system 100 can additionally or alternatively support dynamic TTI durations.

[0062] Physical channels can be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel can be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel can be defined by a number of symbol periods and can extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more of the UEs 115 can monitor or search control regions for control information according to one or more search space sets, and each search space set can include one or more control channel candidates arranged in an aggregation level of one or more symbol periods. An aggregation level for a control channel candidate can refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets can include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets configured for sending control information to a specific UE 115.

[0063] In some examples, base stations 105 can be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but different geographic coverage areas 110 associated with different technologies can be supported by the same base stations 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communications system 100 can include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0064] The wireless communications system 100 can be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 can be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. UEs 115 can be designed to support ultra-reliable, low-latency, or mission critical functions (e.g., mission critical function). Ultra-reliable communications can include private communication or group communication and can be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions can include prioritization of services, and the mission critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low- latency can be used interchangeably herein.

[0065] In some examples, UEs 115 can also be able to communicate directly with other UEs 115 using a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communications can be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group can be outside the geographic coverage area 110 of a base station 105 or be otherwise unserved by a base station 105. In some examples, groups of the UEs 115 communicating via D2D communications can utilize a one-to-many (1:M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the D2D communications between UEs 115 by transmitting

[0066] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an evolved packet core (EPC) or 5G core (5GC), which can include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity can manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the core network 130. User IP packets can be transferred through the user plane entity, which can provide IP address allocation as well as other functions. The user plane entity can be connected to the network operators IP services 150. The operators IP services 150 can include access to the Internet, Intranet, IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service.

[0067] Some of the network devices, such as a base station 105, can include subcomponents such as an access network entity 140, which can be an example of an access node controller (ANC). Each access network entity 140 can communicate with UEs 115 through one or more other access network transmission entities 145, which can be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transmission entity 145 can include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 can be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105).

[0068] The wireless communications system 100 can operate using one or more frequency bands, often in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. The UHF region includes bands such as the 700 MHz, 800 MHz, 900 MHz, 1.4 GHz, 1.9 GHz, and 2.1 GHz bands. The region from 3 GHz to 30 GHz is known as the super-high frequency (SHF) region or centimeter band, since the wavelengths range from approximately one centimeter to one meter in length. The SHF region includes bands such as the 5 GHz band. The region from 30 GHz to 300 GHz is known as the extremely high frequency (EHF) region or millimeter band, since the wavelengths range from approximately one millimeter to one centimeter in length. The EHF region includes bands such as the 38 GHz and 60 GHz bands. The wireless communications system 100 can support millimeter wave (mmW) communications between UEs 115 and base stations 105, and EHF antenna

[0069] The wireless communications system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 can employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed frequency band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed frequency

[0070] Base stations 105 or UEs 115 can be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. Base stations 105 or UEs 115 can use their multiple antennas to improve the reliability and throughput of communications. For instance, base stations 105 can use beamforming to focus energy in a communication signal towards a particular set of UEs 115 that are located within a beam coverage area or cell of the base station 105. This directionality of communications can enable spatial reuse of spectrum, increasing the overall capacity of the wireless communications system 100. A receiving device, such as a UE 115, can determine the beam direction of a communication link with a base station 105 by iterating a beam sweep during initial access. The beam sweep can be performed sequentially in different sets of beams. To reduce the time for

[0071] Beamforming, which can also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer a beam of energy in a specific direction, such as along a line-of-sight. Beamforming can be achieved by combining the signals communicated by antennas of an array of antennas. The signals can be combined in phase and / or amplitude. The signals can be made to appear to come from a direction that is different from the physical location of the array of antennas. In some examples, a transmitting device can use beamforming to transmit signals to a receiving device as a spatial beam, rather than an omnidirectional beam, to improve the efficiency and stability of communications between the devices. In some examples, a receiving device can use beamforming to create beams that can be directed to a transmitting device, such as a base station 105, to improve the

[0072] The wireless communications system 100 includes base stations 105, UEs 115, satellites 120, and a core network 130. In some examples, the wireless communications system 100 can be an LTE network, an LTE-A network, an LTE-A Pro network, or a NR network. In some cases, wireless communications system 100 can support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

[0073] The wireless communications system 100 can also include one or more satellites 120. The satellites 120 can communicate with base stations 105 (also referred to as gateways in an NTN) and UEs 115 (or other high-altitude or terrestrial communication devices). The satellites 120 can be any suitable type of communication satellite configured to relay communications between different end nodes in the wireless communications system. The satellites 120 can be examples of space satellites, balloons, dirigibles, airplanes, drones, unmanned aerial vehicles, etc. In some examples, the satellites 120 can be in a geosynchronous or geostationary orbit, a near-earth orbit, or a medium-earth orbit. The satellites 120 can be multi-beam satellites configured to provide service for multiple service beam coverage areas in a predefined geographic service area. The satellites 120 can be at any distance from the earth’s surface.

[0074] In some cases, a cell can be provided or established by a satellite 120 as part of a non-terrestrial network. In some cases, the satellite 120 can perform the functions of a base station 105, acting as a bent pipe satellite, or can act as a regenerative satellite, or a combination thereof. In other cases, the satellite 120 can be an example of a smart satellite or an intelligent satellite. For example, a smart satellite can be configured to perform more functions than a regenerative satellite (e.g., can be configured to perform specific algorithms in addition to the algorithms used in a regenerative satellite, can be configured to be reprogrammed, etc.). A bent pipe transponder or satellite can be configured to receive signals from a ground station and transmit those signals to a different ground station. In some cases, a bent pipe transponder or satellite can amplify signals or convert from an uplink frequency to a downlink frequency. A regenerative transponder or satellite can be configured to relay signals as a bent pipe transponder or satellite, but can also use on-board processing to perform other functions. Examples of those other functions can include demodulating received signals, decoding received signals, re-encoding signals to be transmitted, or modulating signals to be transmitted, or a combination thereof. For example, a bent pipe satellite (e.g., satellite 120) can receive signals from a base station 105 and can relay the signal to a UE 115 or a base station 105, or vice versa.

[0075] UE 115 may communicate with satellite 120 and / or base station or gateway 105 using communication link 125. In some cases, timing adjustments to communication link 125 that account for propagation delay via satellite 120 may include propagation delay between UE 115 and satellite 120, or propagation delay between base station 105 and satellite 120, or both, as well as variations in propagation delay due to movement of the satellite. According to various techniques discussed herein, UE 115 may account for variations in propagation delay in addition to the determined propagation delay when determining uplink timing for uplink communications via satellite 120.

[0076] Figure 2 An example of a wireless communication system 200 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include a gateway 105-a, a UE 115-a, and a satellite 120-a, which can be the same as those described above with reference to FIG. Figure 1 Examples of base stations 105, UEs 115, and satellites 120 are depicted. Gateway 105-a may serve coverage area 110-a in the example of a terrestrial network, while satellite 120-a may serve coverage area 110-a in the example of an NTN.

[0077] In some examples, satellite 120-a may relay communications between gateway 105-a and UE 115-a. For example, gateway 105-a may communicate with UE 115-a via satellite 120-a, and vice versa. In some examples, for communications initiated at gateway 105-a and destined for UE 115-a, gateway 105-a may transmit an uplink transmission 205-a to satellite 120-a, which may be referred to as a serving link. Satellite 120-a may relay uplink transmission 205-a to UE 115-a as a downlink transmission 205-b, which may be referred to as a feeder link. In other examples, for communications initiated at UE 115-a and destined for gateway 105-a, UE 115-a may transmit an uplink transmission 210-a to satellite 120-a via a feeder link. Satellite 120 - a may relay uplink transmission 210 - a as downlink transmission 210 - b to gateway 105 - b via a serving link.

[0078] Gateway 105-a and satellite 120-a can be thousands of kilometers apart, and it can take some time for electromagnetic waves to propagate the distance between gateway 105-a and satellite 120-a, and between satellite 120-a and UE 115-a. Propagation delays for non-terrestrial networks can be many orders of magnitude larger than propagation delays for terrestrial networks. As such, round trip delays associated with transmissions can also be many orders of magnitude larger for non-terrestrial networks than for terrestrial networks. Moreover, the high speed of non-geostationary satellites (e.g., such as satellite 120-a) can facilitate variations in round trip delays. As a result, UE 115-a can experience variations in uplink timing synchronization with satellite 120-a. Likewise, gateway 105-a can experience variations in uplink and downlink timing synchronization with satellite 120-a. Thus, the total propagation delay can include a first portion of the propagation delay and a first propagation delay variation for the UE-to-satellite link, and a second portion of the propagation delay and a second propagation delay variation for the satellite-to-gateway link. In some cases, the round trip delay information can include a propagation delay from the satellite to the gateway, where the UE determines a propagation delay from the UE to the satellite, and where the propagation delay variation is determined based on a duration for determining a plurality of propagation delays.

[0079] As an example, satellite 120-a can be in an orbit, such as a low earth orbit, a medium earth orbit, or a non-geostationary orbit. In any of these examples, satellite 120-a can be thousands of kilometers from the earth, and thus can be thousands of kilometers from gateway 105-a and UE 115-a. Each transmission 205 or 210 between gateway 105-a and UE 115-a can thus travel that distance from the earth to satellite 120-a and back to the earth. The distance traveled by the transmissions can increase the propagation delay of the transmissions or the round trip delay associated with the transmissions. A propagation delay can refer to the time taken for a signal to travel from a source to an intended recipient. A round trip delay can refer to the time taken for a transmission to be transmitted from a source to an intended recipient, processed by the intended recipient, and transmitted back to the source from the intended recipient in response to the transmission.

[0080] UE 115-a can support closed loop timing control to maintain uplink timing synchronization (or uplink timing accuracy) with satellite 120-a or gateway 105-a. In some examples, when UE 115-a is unable to determine its geographic location within geographic coverage area 110-a, UE 115-a can rely on network signaled round trip delay information or round trip delay rate of change (e.g., of a beam center of satellite 120-a). When satellite 120-a is in a low earth orbit, satellite 120-a can be between 600 km to 2000 km from the earth and travel at a rate of 7.5 km / s. In examples of low earth orbit locations of satellite 120-a, for example, such as an orbit 1200 kilometers from the earth with a 30° elevation angle, the round trip delay rate of change can be on the order of 35 microseconds (ps) per second (ps / s).

[0081] To provide synchronized uplink and downlink timing at gateway 105-a, communications to and from gateway 105-a can be made according to a gateway 105-a timing reference. UE 115-a can adjust the timing of uplink communications to gateway 105-a such that the uplink communications are transmitted far enough in advance of timing boundaries or frame boundaries at gateway 105-a to have a time of arrival at gateway 105-a corresponding to the timing boundaries or frame boundaries. In other cases, UE 115-a can use a satellite 120-a timing reference for uplink communications such that the uplink communications are received at satellite 120-a at a desired time or frame boundary. In either case, satellite 120-a can have sufficient propagation delay variation such that UE 115-a uplink timing can be based on the propagation delay and the propagation delay variation. Figure 3 Examples of a gateway timing reference are illustrated in accordance with various aspects of the disclosure, it should be understood that such relative timing references can be applied in cases where a satellite timing reference is used for determining uplink transmission timing.

[0082] Figure 3 Examples of a frame timing 300 that supports timing adjustment in non-terrestrial wireless communications are illustrated in accordance with aspects of the disclosure. In some examples, frame timing 300 can implement aspects of wireless communications system 100 or 200. For example, frame timing 300 can be based on configurations made by gateway 105 and can be implemented by UE 115 for estimating and determining uplink timing in non-terrestrial networks, as described with reference to Figure 1 and 2

[0083] ​In this example, the gateway timing 305 may have several frame boundaries corresponding to the system frame number (SFN). The UE downlink timing 310 may lag behind the gateway timing 305 by an amount of propagation delay between the UE and the gateway, which may include the UE to satellite propagation delay and the satellite to gateway propagation delay. In order to provide uplink communications received at the gateway and synchronized with the SFN boundaries, the UE uplink timing 315 may advance each corresponding SFN by an amount of a round trip delay 325 compared to the UE downlink timing 310, which may take into account the propagation delay variation due to the speed of the satellite relative to the UE and the base station. In this example, for initial access, the UE may transmit a random access request to the gateway via the satellite to initiate connection establishment. In some cases, the initial round trip delay value of the random access request may be broadcast by the gateway and may be sufficient for the gateway to receive and decode the random access request even in the presence of some timing error. The gateway may transmit a random access response (RAR) and a timing advance (TA) value 320 to the UE in response to the random access request. In some cases, the gateway may also provide information related to the propagation delay variation. Figure 3 In the example of , the gateway may schedule the UE to transmit uplink transmissions in SFN 4. Based on the timing advance and propagation delay variation, the UE may determine uplink timing 330 for SFN 4 such that uplink transmissions from the UE arrive at the gateway aligned with SFN 4 frame boundaries via the satellite.

[0084] In the case where the gateway timing reference is used to determine the uplink timing 330, the total one-way propagation delay corresponds to the delay (D UE ) plus the delay between the satellite and the gateway (D sat For example, in the case where the UE has Global Navigation Satellite System (GNSS) capabilities, the UE may be able to estimate DUE, but may not know DUE due to satellite speed or switching of feeder links. sat According to various aspects of the present disclosure, for the case where a reference timing is set at a gateway, a method for determining D sat and D sat In scenarios where satellite reference timing is used, the serving link can be aligned according to the satellite clock, and the gateway can adjust its transmit timing to compensate for the delay between the satellite and the gateway, and thus the UE does not need to account for timing variations of the feeder link due to movement of the satellite relative to the gateway.

[0085] In a scenario where the UE uses a gateway timing reference, when the UE receives an uplink schedule (e.g., in the downlink control information of a downlink message from the gateway), the UE may determine the uplink timing based on the received downlink signal timing plus the timing advance, plus the offset notified by signaling, plus the timing change calculated based on the propagation delay change. Because the reference timing is set at the gateway (e.g., a ground-based gateway), both the feeder link (gateway to satellite) and the service link (satellite to UE) round-trip delays may be considered. In some cases, the gateway or other network node may broadcast information about the RTD (e.g., to be used in initial access (such as a random access procedure)). In such scenarios, the gateway may broadcast the RTD between the gateway and the satellite. Additionally, the gateway may broadcast the RTD between the satellite and the UE (considering the beam center as the reception point). Alternatively, the gateway may broadcast the RTD between the gateway and the UE (e.g., considering both the gateway to satellite link and the satellite to UE link, considering the beam center as the reception point). In some cases, the broadcast of the RTD information may be performed periodically (eg, with a period P1 , which may be a fixed specified value, or may be configurable and signaled to the UE).

[0086] Because RTD can change due to the movement of satellite and / or UE, the gateway can broadcast information about RTD change for subsequent uplink transmission. In some cases, the gateway can broadcast the RTD change between the gateway and the satellite. Additionally, in some cases, the gateway can broadcast the RTD change between the satellite and the UE (for example, considering the beam center as the receiving point). In some cases, the broadcast to the RTD change can be carried out periodically (for example, with a period P2 that can be different from P1, wherein P2 can be a fixed specified value, or can be a configurable concurrent signaling notification to the UE). In some cases, the RTD change can be signaled with a periodicity different from the RTD (for example, more frequently than the RTD itself). Alternatively, when the UE is in connected mode, the RTD change can be provided in a UE-specific manner via dedicated signaling (for example, in radio resource control (RRC) signaling or in MAC-CE). Although the various examples described herein provide that a gateway may transmit information related to RTD, in other scenarios, the RTD information, configuration information, or a combination thereof may be provided by one or more other network nodes in the wireless communication system, such as a different base station or access point that may provide configuration information, RTD information, RTD change information, or a combination thereof.

[0087] In some cases, the UE may determine the RTD between the UE and the satellite based on one or more of the UE's GNSS capabilities, ephemeris information associated with the satellite, information provided by the gateway (e.g., in broadcast or unicast), or any combination thereof. In some cases, the gateway may not provide a displayed indication of the RTD change, and the UE may estimate the RTD change using periodically provided RTD information. For example, the UE may obtain the RTD at time t-1 and time t, and may estimate the RTD change as (RTD t –RTD t-1 ) / P1. In other cases, the RTD change may not be provided by the gateway, and the UE may determine the RTD change based on the location of the gateway. In such cases, the UE may calculate the RTD and RTD change between the UE and the gateway. In some cases, when the UE is in connected mode (for example, during the registration process), the location of the gateway may be securely provided to the UE via dedicated RRC signaling. In such cases, a UE with GNSS capability may estimate the RTD and RTD change between the satellite and the gateway. Further, in such cases, the system broadcast value of RTD may be used for initial RRC connection. In other cases, the gateway geographic location or any other virtual geographic location may be used to determine the RTD and RTD change, wherein the virtual geographic location is selected so that the rate of change is the same as the real geographic location / such virtual geographic location information may be broadcast or provided to the UE by dedicated signaling. The UE may use this virtual geographic location to calculate the RTD change. In such cases, the RTD value with the real gateway may be broadcast.

[0088] In the case where the satellite timing reference is used for UE uplink timing, the UE can calculate the RTD only between the UE and the satellite and the timing variation for the RTD. In such a case, the UE does not consider the RTD variation between the satellite and the gateway. In some cases, the RTD between the satellite and the gateway may be broadcast for initial access.

[0089] As discussed herein, in some cases, a network (e.g., via a gateway in communication with the UE via satellite, or via another network node) may provide configuration information to one or more UEs that may configure the UE in the NTN and provide an indication of whether to use gateway RTD and RTD variation along with the gateway timing reference for uplink timing, or whether to use satellite RTD and RTD variation along with the satellite timing reference for uplink timing. For example, the configuration information may include a variable (e.g., X) that may be broadcast, where a value of X>0 may indicate that gateway RTD and RTD variation are used, while a value of X=0 may indicate that gateway RTD is not used for initial access or timing advance. In some cases, the configuration information may be provided in a system information broadcast (e.g., in a system information block (SIB) such as a SIB1 broadcast or in an NTN-specific SIB). In other cases, the configuration may be pre-specified, and the network may not need to provide any signaling to indicate whether gateway or satellite RTD and RTD variation are used. In further scenarios, the configuration may be provided to the UE in UE-specific signaling (e.g., in RRC signaling, in MAC-CE, etc.). In such scenarios, the UE may need to be paged to change the indication when in idle mode. In some cases, a zero RTD change may be used for initial access. An example of broadcast signaling indicating the uplink timing reference in the SIB is indicated starting with the following upTimeReference-r16 parameter:

[0090]

[0091] In some cases, if "ulTimeReference" is set to "useGatewayTime", the UE uses compensation due to RTD and RTD variation between the satellite and the gateway using the values ​​provided by rtd-Offset-r16 and rtd-variation-r16. Otherwise (if "ulTimeRefernce" is set to "useSatelliteTime"), the UE only applies compensation for RTD variation between the UE and the satellite (e.g., values ​​calculated by the UE or broadcast). In some cases, if "ulTimeReference" is not present, "rtd-Offset-r16" and "rtd-variation-r16" are not provided. In some cases, this indication for "ulTimeReference" may be indicated in the MIB or in an NTN-specific MIB for NTN that is defined to accommodate these parameters.

[0092] As discussed, in some cases, the network can provide periodic updates to RTD and RTD changes. In some cases, the RTD and RTD changes broadcast in the system information can be periodically updated by the gateway (or other network node). However, this change in system information may not trigger the system information update procedure at the UE. In some cases, in order to trigger the system information update at the UE, one or more validity timers associated with RTD, RTD changes, or both can be established. In some cases, the same or different values ​​of the remaining validity time or life span of RTD and RTD changes can be indicated in the broadcast information. In such cases, the gateway can keep updating the remaining time without knowing the UE. After the expiration, the UE re-acquires the system information with the updated propagation delay information. Examples of broadcast information providing the remaining validity of propagation delay information are:

[0093]

[0094] In other cases, the same or different modification periodicities (p) may be defined for the updating of RTD and RTD changes (e.g., hard-coded or provided in the SIB). In such cases, the start of the modification period may be at SFN mod p.=0. Thus, at every p. SFNs, the UE may update the parameters (i.e., once per modification period). In other cases, when the UE obtains the parameters in a broadcast transmission (e.g., in the SIB), the UE may start a validity timer. Upon expiration of the validity timer, the UE may obtain the broadcast transmission again to update the parameters. In other cases, a paging procedure may be used to indicate that the RTD and RTD changes have been updated. For example, a new update indication bit may be provided in the downlink control information (DCI) used for paging, a direct indication may be provided in the DCI, or a new paging RNTI may be defined so that a UE receiving paging scrambled by the new paging RNTI will update the RTD and RTD change parameters. In some cases, separate update indications, validity timers, paging techniques, or a combination thereof may be used for RTD and RTD changes so that RTD may be updated independently of RTD changes (eg, according to different periodicities).

[0095] Figure 4 An example of a process flow 400 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated. The process flow 400 may be implemented as described with reference to Figure 1 and 2 For example, the process flow 400 may be based on a configuration performed by a network and may be implemented by a UE to identify propagation delay and propagation delay variation for use in determining uplink timing in a non-terrestrial network, as described with reference to FIG. Figure 1 and 2 described.

[0096] Process flow 400 may include gateway 105-b, UE 115-b, and satellite 120-b, which may be as described with reference to FIG. Figure 1 and 2 Examples of gateway 105, UE 115, and satellite 120 are described. In the following description of process flow 400, operations between gateway 105-b, UE 115-b, and satellite 120-b may be delivered in a different order than the example order shown, or operations performed by gateway 105-b, UE 115-b, and satellite 120-b may be performed in a different order or at different times. Some operations may also be omitted from process flow 400, and other operations may be added to process flow 400. Figure 4 In the example of FIG, gateway 105-b, UE 115-b, and satellite 120-b may communicate with each other via a non-terrestrial network. Process flow 400 may support higher data rates, improved mobility support for UE 115-b in the non-terrestrial network, and other benefits.

[0097] At 405, gateway 105-b may determine that a gateway timing reference is to be used for communications with UE 115-b. At 410, gateway 105-b may transmit configuration information to UE 115-b indicating that the gateway timing reference is to be used for uplink communication timing of UE 115-b. In some cases, the configuration information may be provided in a broadcast transmission from gateway 105-b, such as those discussed herein.

[0098] At 415, UE 115-b may identify that a gateway timing reference is to be used for uplink timing determination. In some cases, UE 115-b may decode broadcast information indicating that a gateway timing reference is to be used and also indicating a propagation delay value and a propagation delay variation. At 420, gateway 105-b may estimate the RTD and RTD variation between UE 115-b and gateway 105-b. In some cases, the RTD and RTD variation may be based on the propagation delay value and propagation delay variation between gateway 105-b and satellite 120-b, and based on the propagation delay value and propagation delay variation between satellite 120-b and UE 115-b (e.g., based on a beam center considered as a reception point). In some cases, the gateway 105-b may use the location information of the gateway 105-b (e.g., a provided location, a location determined based on GNSS, or a virtual geographic location), the location information of the UE 115-b (e.g., based on a beam center reception point or based on location information associated with the UE 115-b), and the location information of the satellite 120-b (e.g., based on GNSS, ephemeris information of the satellite 120-b, or a combination thereof) to determine propagation delay and propagation delay variation parameters that are then provided to the UE 115-b. At 425, the gateway 105-b may transmit the RTD information to the UE 115-b. In some cases, the RTD information may include information related to a validity time that indicates when the UE 115-b is to monitor for new broadcast information to update the RTD information, as discussed herein.

[0099] At 430, UE 115-b can determine the uplink timing for uplink transmission based on RTD and RTD variation. In some cases, the uplink timing can make the associated uplink transmission received at gateway 105-b synchronized with frame boundaries or otherwise synchronized with the configured uplink resources allocated to UE 115-b for associated uplink transmission. At 435, UE 115-b and gateway 105-b can perform uplink and downlink communication via satellite 120-b. As discussed herein, uplink timing for uplink communication can be determined based on indicated RTD and RTD variation. In some cases, gateway 105-b and UE 115-b can periodically update RTD and RTD variation so that uplink timing can be determined based on the current estimate of RTD and RTD variation.

[0100] Figure 5 An example of a process flow 500 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is illustrated. The process flow 500 may be implemented as described with reference to Figure 1 and 2For example, the process flow 500 may be based on configuration by the gateway 105-c and may be implemented by the UE 115-c to identify propagation delay and propagation delay variation for use in determining uplink timing in a non-terrestrial network, as described with reference to FIG. Figure 1 and 2 described.

[0101] The process flow 500 may include a gateway 105-c, a UE 115-c, and a satellite 120-c, which may be as described with reference to FIG. Figure 1 and 2 Examples of gateway 105, UE 115, and satellite 120 are described. In the following description of process flow 500, operations between gateway 105-c, UE 115-c, and satellite 120-c may be delivered in a different order than the example order shown, or operations performed by gateway 105-c, UE 115-c, and satellite 120-c may be performed in a different order or at different times. Some operations may also be omitted from process flow 500, and other operations may be added to process flow 500. Figure 5 In the example of FIG, gateway 105-c, UE 115-c, and satellite 120-c may communicate with each other via a non-terrestrial network. Process flow 500 may support higher data rates, improved mobility support for UE 115-c in the non-terrestrial network, and other benefits.

[0102] At 505, the gateway 105-c may determine that a satellite timing reference is to be used for communications with the UE 115-c. At 510, the gateway 105-c may transmit configuration information to the UE 115-c indicating that the satellite timing reference is to be used for uplink communication timing of the UE 115-c. In some cases, the configuration information may be provided in a broadcast transmission from the gateway 105-c, such as those discussed herein.

[0103] At 515, the UE 115-c may identify that a satellite timing reference is to be used for uplink timing determination. In some cases, the UE 115-c may decode broadcast information indicating that a satellite timing reference is to be used and may also indicate a propagation delay value, either alone or in combination with a propagation delay variation (e.g., based on the center of the receive beam of the satellite 120-c).

[0104] At 520, the gateway 105-c may transmit an RTD value for initial access. In some cases, the RTD value for initial access may be provided to the UE 115-c for determining uplink timing for a random access request message. In some cases, an RTD variation of zero may be used for initial access communications. At 525, the UE 115-c and the gateway 105-c may transmit the initial access communication via the satellite 120-c.

[0105] At 530, UE 115-c may determine the RTD and RTD change between UE 115-c and satellite 120-c. In some cases, the RTD and RTD change may be determined based on location information provided about satellite 120-c and location information associated with UE 115-c. In some cases, a GNSS component at UE 115-c may be used to determine the location of UE 115-c, and ephemeris information from satellite 120-c may be used to determine the satellite 120-c location and orbital information related to the movement of satellite 120-c relative to UE 115-c. In some cases, the RTD and RTD change information may be identified in broadcast or dedicated signaling from gateway 105-c (e.g., based on the location of the beam center of the beam used by satellite 120-c for communication with UE 115-c). In some cases, the signaling providing the RTD and RTD change may provide timing information related to the validity time of the RTD and RTD change information.

[0106] At 535, UE 115-c can determine uplink timing for uplink transmission based on RTD and RTD variation, wherein the uplink timing uses satellite timing reference. In some cases, uplink timing can synchronize the associated uplink transmission received at satellite 120-c with frame boundaries or otherwise synchronize with the configured uplink resources allocated to UE 115-c for associated uplink transmission. At 540, UE 115-c and gateway 105-c can perform uplink and downlink communication via satellite 120-c. As discussed herein, uplink timing for uplink communication can be determined based on determined or indicated RTD and RTD variation. In some cases, gateway 105-c and UE 115-c can periodically update RTD and RTD variation so that uplink timing can be determined based on the current estimate of RTD and RTD variation.

[0107] Figure 6 A block diagram 600 is shown of a device 605 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure. The device 605 can be an example of aspects of the UE 115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0108] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing adjustment in non-terrestrial wireless communications, etc.). The information may be passed to other components of the device 605. The receiver 610 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 610 may utilize a single antenna or a collection of antennas.

[0109] The communication manager 615 may identify a propagation delay for communication between the UE and the base station via a satellite based on round-trip delay information received from a network (e.g., via the base station or another network node); determine an uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and the propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmit the uplink communication to the base station via the satellite based on the uplink timing. The communication manager 615 may be an example of aspects of the communication manager 910 described herein.

[0110] The communication manager 615 can be implemented as described herein to achieve one or more potential advantages. One implementation can allow the device 605 to provide communications with high-altitude vehicles (e.g., satellites or other non-ground-based equipment), user terminals, and base stations in a non-terrestrial network, among other advantages. Further, various implementations can support increased spectral efficiency and, in some examples, facilitate greater mobility support for user terminals in non-terrestrial networks compared to terrestrial networks, among other advantages.

[0111] The communication manager 615 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615 or its subcomponents may be performed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0112] The communication manager 615 or its subcomponents can be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0113] The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 620 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The transmitter 620 may utilize a single antenna or a collection of antennas.

[0114] Figure 7 A block diagram 700 is shown of a device 705 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure. The device 705 can be an example of aspects of the device 605 or UE 115 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 735. The device 705 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0115] The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing adjustment in non-terrestrial wireless communications). The information may be passed to other components of the device 705. The receiver 710 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 710 may utilize a single antenna or a collection of antennas.

[0116] Communications manager 715 may be an example of aspects of communications manager 615 as described herein. Communications manager 715 may include RTD manager 720, transmission timing manager 725, and uplink transmission manager 730. Communications manager 715 may be an example of aspects of communications manager 910 as described herein.

[0117] The RTD manager 720 may identify a propagation delay for communications between a UE and a base station via a satellite based on round-trip delay information received from the network.

[0118] The transmission timing manager 725 can determine an uplink timing for initiating an uplink communication to a base station via a satellite based on a propagation delay and a propagation delay variation, where the uplink timing is determined with respect to a satellite timing reference or a base station timing reference, and where the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station.

[0119] The uplink transmission manager 730 can transmit, to the base station via the satellite, the uplink communication based on the uplink timing.

[0120] The transmitter 735 can transmit signals generated by other components of the device 705. In some examples, the transmitter 735 can be collocated with a receiver 710 in a transceiver module. For example, the transmitter 735 can be a example of a transmitter as described with reference to FIG. 9. The transmitter 735 can utilize a single antenna or a set of antennas. Figure 9

[0121] Figure 8 A block diagram 800 of a communications manager 805 that supports timing adjustment in non-terrestrial wireless communications in accordance with aspects of the present disclosure is shown. The communications manager 805 can be an example of aspects of a communications manager 615, a communications manager 715, or a communications manager 910 described herein. The communications manager 805 can include an RTD manager 810, a transmission timing manager 815, an uplink transmission manager 820, a configuration manager 825, a paging manager 830, a validity timer 835, and a location manager 840. Each of these modules can communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0122] The RTD manager 810 can identify a propagation delay for communications between a UE and a base station via a satellite based on round trip delay information received from a network (e.g., via a base station or another network node). In some examples, the RTD manager 810 can determine a first portion of the propagation delay for a UE-to-satellite link and a first propagation delay variation. In some examples, the RTD manager 810 can determine a second portion of the propagation delay for a satellite-to-base station link and a second propagation delay variation. In some examples, the propagation delay for communications between the UE and the base station is based on one or more of the first portion of the propagation delay, the first propagation delay variation, the second portion of the propagation delay, or the second propagation delay variation.

[0123] ​In some examples, the RTD manager 810 can receive (e.g., from a base station) a broadcast transmission including round-trip delay information, and where the broadcast transmission is periodically broadcasted with a first periodicity. In some cases, the round-trip delay information includes an initial value of a propagation delay for an initial access procedure, and where a propagation delay variation is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined. In some cases, the round-trip delay information includes a satellite-to-base station propagation delay, and where the UE determines a UE-to-satellite propagation delay, and where a propagation delay variation is determined based on a duration for determining a plurality of propagation delays. In some cases, the round-trip delay information further includes the UE-to-satellite propagation delay. In some cases, a midpoint of a transmission beam coverage area of a transmission beam used for communications with the UE is considered a location of the UE for the UE-to-satellite propagation delay.

[0124] In some cases, the round-trip delay information includes a base station-to-UE propagation delay for an initial access procedure, and where a propagation delay variation is determined after the initial access procedure. In some cases, the round-trip delay information includes the propagation delay and the propagation delay variation. In some cases, the propagation delay is transmitted with a first periodicity, while the propagation delay variation is transmitted with a second periodicity different from the first periodicity. In some cases, the first periodicity is a first predefined fixed periodicity, or is configured in signaling transmitted to the UE, and where the second periodicity is a second predefined fixed periodicity or is configured in signaling transmitted to the UE. In some cases, the propagation delay is provided in broadcast signaling, while the propagation delay variation is provided in dedicated signaling to the UE.

[0125] In some cases, the round-trip delay information includes an indication of a propagation delay, and is periodically provided, and where a propagation delay variation is determined based on a difference between two or more instances of the provided propagation delay. In some cases, the propagation delay variation is determined based on a difference between two instances of the propagation delay and a time difference of receiving the two instances of the propagation delay.

[0126] The transmission timing manager 815 can determine an uplink timing for initiating an uplink communication to the base station via the satellite based on the propagation delay and the propagation delay variation, where the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and where the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station. In some cases, the uplink timing for initiating the uplink communication to the base station is based on the satellite timing reference, and the UE-to-satellite propagation delay and the UE-to-satellite propagation delay variation, regardless of the satellite-to-base station propagation delay or the satellite-to-base station propagation delay variability.

[0127] The uplink transmission manager 820 can transmit, via the satellite, the uplink communication to the base station based on the uplink timing. The configuration manager 825 can receive, from the base station, configuration information indicating whether the uplink timing is based on a satellite timing reference and a UE-to-satellite propagation delay or a base station timing reference and a UE-to-gateway propagation delay. In some examples, the configuration information further provides a round trip delay offset associated with the base station and the satellite, and a round trip delay variation associated with the base station and the satellite. In some cases, the configuration information is provided in a system information broadcast transmission from the base station, or in UE-specific signaling from the base station.

[0128] In some cases, the configuration information indicates that the uplink timing is relative to a base station timing reference. In some cases, the configuration information indicates that the uplink timing is based on a satellite timing reference, and wherein the uplink timing is determined based on only a UE-to-satellite propagation delay and a UE-to-satellite propagation delay variation. In some cases, the configuration information is received from the base station in a master information block (MIB).

[0129] The paging manager 830 can receive, from the base station, paging information to update the propagation delay or the propagation delay variation information. In some cases, the paging information is provided in an indication bit in a downlink control information paging indication, in a direct indication in downlink control information, or in a paging indication scrambled with a radio network temporary identifier (RNTI) associated with a round trip delay information update.

[0130] The validity timer 835 can identify a validity time associated with the round trip delay information. In some examples, the validity timer 835 can monitor for updated round trip delay information in response to expiration of the validity time. In some cases, the validity time is based on a predefined modification period or based on configuration information received from the network configuring the modification period, where the UE monitors for updated round trip delay information once per modification period. In some cases, the validity time starts upon acquisition of a SIB containing the round trip delay information, and wherein monitoring for updated round trip delay information includes acquisition of another instance of the SIB.

[0131] The location manager 840 can determine one or more of the propagation delay or the propagation delay variation based on one or more of information from a global navigation satellite system (GNSS) component at the UE, ephemeris information associated with the satellite, information provided by the base station, or any combination thereof.

[0132] In some examples, the location manager 840 may receive an indication of the base station location in the round-trip delay information. In some examples, the location manager 840 may determine one or more of the propagation delay or propagation delay variation based on the base station location, the UE location, and the satellite location. In some cases, the base station location is provided in radio resource control signaling when the UE is in connected mode with the base station. In some cases, the base station location is a virtual geographic location that allows the determination of the propagation delay variation and is provided in dedicated signaling to the UE or broadcast signaling from the base station.

[0133] Figure 9 A diagram of a system 900 including a device 905 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. Device 905 may be an example of, or include components of, device 605, device 705, or UE 115 as described herein. Device 905 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communications manager 910, an I / O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components may be in electronic communication via one or more buses (e.g., bus 945).

[0134] The communication manager 910 can identify a propagation delay for communication between the UE and the base station via a satellite based on round-trip delay information received from the network; determine an uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and the propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmit the uplink communication to the base station via the satellite based on the uplink timing.

[0135] The communication manager 910 can be implemented as described herein to achieve one or more potential advantages. One implementation can allow the device 905 to provide communications with high-altitude vehicles (e.g., satellites or other non-ground-based equipment), user terminals, and base stations in a non-terrestrial network, among other advantages. Further, various implementations can support increased spectral efficiency and, in some examples, facilitate greater mobility support for user terminals in non-terrestrial networks compared to terrestrial networks, among other advantages.

[0136] I / O controller 915 can manage input and output signals for device 905. I / O controller 915 can also manage peripheral devices that are not integrated into device 905. In some cases, I / O controller 915 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 915 can utilize an operating system, such as MS- MS- OS / or another known operating system. In other cases, I / O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 915 may be implemented as part of a processor. In some cases, a user may interact with device 905 via I / O controller 915 or via hardware components controlled by I / O controller 915.

[0137] The transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links, as described herein. For example, the transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0138] In some cases, a wireless device may include a single antenna 925. However, in some cases, the device may have more than one antenna 925, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0139] The memory 930 may include random access memory (RAM) and read-only memory (ROM). The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 930 may contain, among other things, a basic I / O system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0140] The processor 940 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 940 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause the device 905 to perform various functions (e.g., various functions or tasks to support timing adjustment in non-terrestrial wireless communications).

[0141] The code 935 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 935 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 935 may not be directly executed by the processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0142] Figure 10 A block diagram 1000 is shown of a device 1005 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure. The device 1005 can be an example of aspects of a base station 105 or a gateway as described herein. The device 1005 can include a receiver 1010, a communication manager 1015, and a transmitter 1020. The device 1005 can also include a processor. Each of these components can be in communication with each other (e.g., via one or more buses).

[0143] The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing adjustment in non-terrestrial wireless communications). The information may be passed to other components of the device 1005. The receiver 1010 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The receiver 1010 may utilize a single antenna or a collection of antennas.

[0144] The communication manager 1015 may identify round-trip delay information associated with a propagation delay for communicating with at least a first UE via a satellite; determine, based on the round-trip delay information, configuration information instructing the first UE to identify uplink timing for uplink communication to a base station via the satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based on the propagation delay and a propagation delay variation, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmit the configuration information to at least the first UE. The communication manager 1015 may be an example of aspects of the communication manager 1310 described herein.

[0145] The communication manager 1015 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 1015 or its subcomponents may be performed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0146] The communication manager 1015 or its subcomponents can be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0147] The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be co-located with the receiver 1010 in a transceiver module. For example, the transmitter 1020 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The transmitter 1020 may utilize a single antenna or a collection of antennas.

[0148] Figure 11 A block diagram 1100 is shown of a device 1105 that supports timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure. The device 1105 can be an example of aspects of the device 1005, base station 105, or gateway as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1130. The device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0149] The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing adjustment in non-terrestrial wireless communications). The information may be passed to other components of the device 1105. The receiver 1110 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The receiver 1110 may utilize a single antenna or a collection of antennas.

[0150] The communications manager 1115 may be an example of aspects of the communications manager 1015 as described herein. The communications manager 1115 may include an RTD manager 1120 and a configuration manager 1125. The communications manager 1115 may be an example of aspects of the communications manager 1310 as described herein.

[0151] The RTD manager 1120 may identify round trip delay information associated with a propagation delay for communicating with at least a first UE via a satellite.

[0152] The configuration manager 1125 may determine configuration information based on the round-trip delay information, the configuration information indicating that the first UE is to identify uplink timing for uplink communication to the base station via the satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based on propagation delay and propagation delay variation, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmit the configuration information to at least the first UE.

[0153] The transmitter 1130 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1130 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1130 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The transmitter 1130 may utilize a single antenna or a collection of antennas.

[0154] Figure 12 A block diagram 1200 is shown of a communication manager 1205 that supports timing adjustment in non-terrestrial wireless communications in accordance with aspects of the present disclosure. The communication manager 1205 can be an example of aspects of the communication manager 1015, the communication manager 1115, or the communication manager 1310 described herein. The communication manager 1205 can include an RTD manager 1210, a configuration manager 1215, a paging manager 1220, and a transmission timing manager 1225. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0155] The RTD manager 1210 may identify round trip delay information associated with a propagation delay for communicating with at least a first UE via a satellite.

[0156] Configuration manager 1215 may determine, based on the round-trip delay information, configuration information that instructs the first UE to identify uplink timing for uplink communication to the base station via the satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based on propagation delay and propagation delay variation, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station. In some examples, configuration manager 1215 may transmit the configuration information to at least the first UE. In some examples, the configuration information further provides a round-trip delay offset associated with the base station and the satellite, and a round-trip delay variation associated with the base station and the satellite.

[0157] In some examples, the configuration manager 1215 may periodically transmit instances of configuration information with updated round-trip delay information. In some cases, the configuration information includes a variable that indicates, based at least in part on a value of the variable, whether uplink timing is based on a satellite timing reference and a UE-to-satellite propagation delay or based on a base station timing reference and a UE-to-base station propagation delay. In some cases, the configuration information is transmitted in a system information broadcast transmission from the base station or in UE-specific signaling from the first UE. In some cases, the configuration information indicates that the uplink timing is relative to the base station timing reference. In some cases, the configuration information indicates that the uplink timing is based on a satellite timing reference, and wherein the uplink timing is determined solely based on the UE-to-satellite propagation delay. In some cases, the configuration information is transmitted in a master information block (MIB). In some cases, the periodicity of transmitting instances of the configuration information with updated round-trip delay information is based on a predefined modification period or a configured modification period indicated in the configuration information.

[0158] The paging manager 1220 may transmit a paging message to at least the first UE indicating that the first UE is to update the round trip delay information. In some cases, the paging message indicating that the round trip delay information is to be updated is provided in an indication bit in a downlink control information paging indication, in a direct indication in the downlink control information, or in a paging indication scrambled with a radio network temporary identifier (RNTI) associated with the round trip delay information update.

[0159] The transmission timing manager 1225 may determine uplink transmission timing for uplink communications. In some cases, the round trip delay information includes an initial value of a propagation delay for an initial access procedure, and wherein the propagation delay variation is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

[0160] Figure 13 A diagram of a system 1300 including a device 1305 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. Device 1305 may be an example of, or include components of, device 1005, device 1105, base station 105, or gateway as described herein. Device 1305 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, a memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350).

[0161] The communication manager 1310 can identify round-trip delay information associated with a propagation delay for communication with at least a first UE via a satellite; determine configuration information based on the round-trip delay information, the configuration information instructing the first UE to identify uplink timing for uplink communication to a base station via a satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based on the propagation delay and a propagation delay variation, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmit the configuration information to at least the first UE.

[0162] The network communications manager 1315 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1315 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0163] The transceiver 1320 can communicate bidirectionally via one or more antennas, wired or wireless links, as described herein. For example, the transceiver 1320 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1320 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0164] In some cases, a wireless device may include a single antenna 1325. However, in some cases, the device may have more than one antenna 1325, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0165] Memory 1330 may include RAM, ROM, or a combination thereof. Memory 1330 may store computer-readable code 1335 including instructions that, when executed by a processor (e.g., processor 1340), cause the device to perform the various functions described herein. In some cases, memory 1330 may include, among other things, a BIOS that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0166] Processor 1340 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1340 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1340. Processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1330) to cause device 1305 to perform various functions (e.g., various functions or tasks to support timing adjustment in non-terrestrial wireless communications).

[0167] The inter-site communication manager 1345 can manage communications with other base stations 105 and can include a controller or scheduler for controlling communications with the UE 115 in coordination with the other base stations 105. For example, the inter-site communication manager 1345 can coordinate the scheduling of transmissions to the UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-site communication manager 1345 can provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between the base stations 105.

[0168] The code 1335 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 1335 may not be directly executed by the processor 1340, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0169] Figure 14 14. A flow chart illustrating a method 1400 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by the UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0170] At 1405, the UE may identify a propagation delay for communication between the UE and the base station via a satellite based on round-trip delay information received from the network (e.g., from the base station or another network node). The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0171] At 1410, the UE may determine uplink timing for initiating uplink communication to a base station via a satellite based on propagation delay and propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed as described with reference to Figures 6 to 9 The described transmission timing manager is executed.

[0172] At 1415, the UE may transmit uplink communications to the base station via the satellite based on the uplink timing. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be as described with reference to Figures 6 to 9 The uplink transmission manager described is executed.

[0173] Figure 15 A flow chart illustrating a method 1500 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by the UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0174] At 1505, the UE may identify a propagation delay for communication between the UE and a base station via a satellite based on round-trip delay information received from the network. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0175] At 1510, the UE may determine a first portion of a propagation delay and a first propagation delay variation for a UE-to-satellite link. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0176] At 1515, the UE may determine a second portion of the propagation delay and a second propagation delay variation for the satellite-to-base station link. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0177] At 1520, the UE may determine an uplink timing for initiating uplink communication to the base station via the satellite, wherein the propagation delay for communication between the UE and the base station is based on one or more of a first portion of the propagation delay, a first propagation delay variation, a second portion of the propagation delay, or a second propagation delay variation. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed as described with reference to Figures 6 to 9 The described transmission timing manager is executed.

[0178] At 1525, the UE may transmit uplink communications to the base station via the satellite based on the uplink timing. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be as described with reference to Figures 6 to 9 The uplink transmission manager described is executed.

[0179] Figure 16 1. A flow chart illustrating a method 1600 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0180] Optionally, at 1605, the UE may receive configuration information indicating whether uplink timing is based on a satellite timing reference and a UE-to-satellite propagation delay or a base station timing reference and a UE-to-gateway propagation delay. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed as described with reference to Figures 6 to 9 The configuration manager described here is executed.

[0181] At 1610, the UE may receive paging information to update propagation delay or propagation delay variation information and update based on the paging information. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be as described with reference to Figures 6 to 9 In some cases, the paging information is provided in an indication bit in a downlink control information paging indication, in a direct indication in the downlink control information, or in a paging indication scrambled with an RNTI associated with a round trip delay information update.

[0182] At 1615, the UE may identify a propagation delay for communication between the UE and the base station via the satellite based on the updated round-trip delay information. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0183] At 1620, the UE may determine an uplink timing for initiating uplink communication to the base station via the satellite based on the propagation delay and the propagation delay variation. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be as described with reference to Figures 6 to 9 The described transmission timing manager is executed.

[0184] At 1625, the UE may transmit uplink communications to the base station via the satellite based on the uplink timing. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be as described with reference to Figures 6 to 9 The uplink transmission manager described is executed.

[0185] Figure 17 1. A flow chart illustrating a method 1700 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0186] At 1705, the UE may identify a propagation delay for communication between the UE and the base station via a satellite based on the round-trip delay information received from the network. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed as described with reference to Figures 6 to 9 The RTD manager described is executed.

[0187] At 1710, the UE may determine uplink timing for initiating uplink communication to a base station via a satellite based on propagation delay and propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed as described with reference to Figures 6 to 9 The described transmission timing manager is executed.

[0188] At 1715, the UE may transmit uplink communications to the base station via the satellite based on the uplink timing. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be as described with reference to Figures 6 to 9 The uplink transmission manager described is executed.

[0189] At 1720, the UE may identify a validity time associated with the round trip delay information. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be as described with reference to Figures 6 to 9 The validity timer described is implemented.

[0190] At 1725, the UE may monitor the updated round trip delay information in response to the expiration of the validity time. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be as described with reference to Figures 6 to 9 The validity timer described is implemented.

[0191] Figure 18 A flow chart illustrating a method 1800 for supporting timing adjustment in non-terrestrial wireless communications according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by a base station 105 or a gateway or components thereof as described herein. For example, the operations of the method 1800 may be implemented by a base station 105 or a gateway or components thereof as described herein. Figures 10 to 13 In some examples, a base station or gateway may execute an instruction set to control functional elements of the base station or gateway to perform the functions described herein. Additionally or alternatively, a base station or gateway may use dedicated hardware to perform various aspects of the functions described herein.

[0192] At 1805, the base station or gateway may identify round trip delay information associated with a propagation delay for communicating with at least a first UE via a satellite. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed as described with reference to Figures 10 to 13 The RTD manager described is executed.

[0193] At 1810, the base station or gateway may determine configuration information based on the round-trip delay information, the configuration information instructing the first UE to identify uplink timing for uplink communications to the base station via the satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based on propagation delay and propagation delay variation, and wherein the propagation delay variation is based on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed as described with reference to Figures 10 to 13 The configuration manager described here is executed.

[0194] At 1815, the base station or gateway may transmit configuration information to at least the first UE. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed as described with reference to Figures 10 to 13The configuration manager described here is executed.

[0195] At 1820, the base station or gateway may periodically transmit an instance of the configuration information with updated round-trip delay information. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed as described with reference to Figures 10 to 13 In some cases, the periodicity of instances of transmitting configuration information with updated round trip delay information is based on a predefined modification period or a configured modification period indicated in the configuration information.

[0196] The following provides an overview of various aspects of the disclosure:

[0197] Aspect 1: A method for wireless communication at a UE, comprising: identifying a propagation delay for communication between the UE and a base station via a satellite based at least in part on round-trip delay information received from a network; determining uplink timing for initiating uplink communication to the base station via the satellite based at least in part on the propagation delay and propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a base station timing reference, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmitting the uplink communication to the base station via the satellite based at least in part on the uplink timing.

[0198] Aspect 2: The method of Aspect 1, further comprising: determining a first portion of the propagation delay and a first propagation delay variation for a UE-to-satellite link; determining a second portion of the propagation delay and a second propagation delay variation for a satellite-to-base station link; and wherein the propagation delay for communication between the UE and the base station is based at least in part on one or more of the first portion of the propagation delay, the first propagation delay variation, the second portion of the propagation delay, or the second propagation delay variation.

[0199] Aspect 3: The method according to any one of aspects 1 to 2 further comprises: receiving configuration information indicating whether the uplink timing is based on a satellite timing reference and a propagation delay from the UE to the satellite, or based on a base station timing reference and a propagation delay from the UE to the gateway.

[0200] Aspect 4: The method of aspect 3, wherein the configuration information is provided in a system information broadcast transmission or in UE-specific signaling.

[0201] Aspect 5: A method as in any one of Aspects 3 to 4, wherein the configuration information indicates that the uplink timing is relative to a base station timing reference; and wherein the configuration information further provides a round-trip delay offset associated with the base station and the satellite and a round-trip delay variation associated with the base station and the satellite.

[0202] Aspect 6: The method according to any one of aspects 3 to 5, wherein the configuration information indicates that the uplink timing is based on a satellite timing reference, and the uplink timing is determined based only on a propagation delay from the UE to the satellite and a propagation delay variation from the UE to the satellite.

[0203] Aspect 7: The method of any one of aspects 1 to 6, further comprising: identifying a validity time associated with the round trip delay information; and monitoring the updated round trip delay information in response to expiration of the validity time.

[0204] Aspect 8: The method of aspect 7, wherein the validity time starts when a SIB containing the round trip delay information is acquired, and monitoring the updated round trip delay information includes acquiring another instance of the SIB.

[0205] Aspect 9: The method of any one of aspects 1 to 8, wherein the round trip delay information comprises an initial value of a propagation delay for an initial access procedure, and the propagation delay variation is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

[0206] Aspect 10: The method of any one of aspects 1 to 9, wherein the round trip delay information comprises a satellite to base station propagation delay, and the UE determines a UE to satellite propagation delay, and the propagation delay variation is determined based on a duration over which a plurality of propagation delays are determined.

[0207] Aspect 11: The method of aspect 10, wherein the round trip delay information further includes a propagation delay from the UE to the satellite.

[0208] Aspect 12: The method of aspect 11, wherein a midpoint of a transmission beam coverage area of ​​a transmission beam used for communication with the UE is considered as the position of the UE for UE-to-satellite propagation delay.

[0209] Aspect 13: The method according to any one of aspects 1 to 12, wherein the round trip delay information comprises a base station to UE propagation delay for an initial access procedure, and the propagation delay variation is determined after the initial access procedure.

[0210] Aspect 14: The method of any one of aspects 1 to 13, wherein identifying further comprises: receiving a broadcast transmission comprising round trip delay information, and wherein the broadcast transmission is periodically broadcast by the base station or another network node with a first periodicity.

[0211] Aspect 15: The method of any one of aspects 1 to 14, wherein the round trip delay information includes propagation delay and propagation delay variation.

[0212] Aspect 16: The method of aspect 15, wherein the propagation delay is provided in broadcast signaling and the propagation delay variation is provided in dedicated signaling to the UE.

[0213] Aspect 17: A method as described in any of Aspects 1 to 16, wherein the round-trip delay information includes an indication of the propagation delay and is provided periodically by the base station, and the propagation delay change is determined at least in part based on the difference between two or more instances of the propagation delay provided by the base station.

[0214] Aspect 18: A method as in any of Aspects 1 to 17, wherein identifying comprises: receiving an indication of a base station location in round-trip delay information; and determining one or more of the propagation delay or the propagation delay variation based at least in part on the base station location, the UE location, and the satellite location.

[0215] Aspect 19: The method of method 18, wherein when the UE is in connected mode with the base station, the base station location is provided in radio resource control signaling.

[0216] Aspect 20: The method of any one of aspects 18 to 19, wherein the base station location is a virtual geographical location that allows determination of propagation delay variation and is provided in dedicated signaling to the UE or broadcast signaling from the base station.

[0217] Aspect 21: A method for wireless communication at a base station, comprising: identifying round-trip delay information associated with a propagation delay for communication with at least a first UE via a satellite; determining configuration information based at least in part on the round-trip delay information, the configuration information instructing the first UE to identify uplink timing for uplink communication to the base station via the satellite based on a satellite timing reference or a base station timing reference, wherein the uplink timing is based at least in part on the propagation delay and a propagation delay variation, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the base station; and transmitting the configuration information to at least the first UE.

[0218] Aspect 22: The method of aspect 21, wherein the configuration information includes a variable that indicates, at least in part based on a value of the variable, whether the uplink timing is based on a satellite timing reference and a propagation delay from the UE to the satellite, or based on a base station timing reference and a propagation delay from the UE to the base station.

[0219] Aspect 23: The method of aspect 22, wherein the configuration information is transmitted in a system information broadcast transmission from the base station or in UE-specific signaling to the first UE.

[0220] Aspect 24: A method as in any one of Aspects 22 to 23, wherein the configuration information indicates that the uplink timing is relative to a base station timing reference; and wherein the configuration information further provides a round-trip delay offset associated with the base station and the satellite and a round-trip delay variation associated with the base station and the satellite.

[0221] Aspect 25: The method according to any one of aspects 22 to 24, wherein the configuration information indicates that the uplink timing is based on a satellite timing reference, and the uplink timing is determined based solely on a UE-to-satellite propagation delay.

[0222] Aspect 26: The method of any one of aspects 21 to 25, further comprising: periodically transmitting instances of the configuration information with updated round-trip delay information.

[0223] Aspect 27: The method of any one of aspects 21 to 26, wherein the round trip delay information comprises an initial value of a propagation delay for an initial access procedure, and the propagation delay variation is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

[0224] Aspect 28: A device for wireless communication at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the device to perform the method of any one of Aspects 1 to 20.

[0225] Aspect 29: An apparatus for wireless communication at a UE, comprising at least one means for performing the method of any one of aspects 1 to 20.

[0226] Aspect 30: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform the method of any one of aspects 1 to 20.

[0227] Aspect 31: An apparatus for performing wireless communication at a base station, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as described in any one of Aspects 21 to 27.

[0228] Aspect 32: An apparatus for wireless communication at a base station, comprising at least one device for performing the method of any one of Aspects 21 to 27.

[0229] Aspect 33: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method of any one of aspects 21 to 27.

[0230] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0231] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used throughout much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0232] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0233] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0234] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or code. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0235] Computer-readable media include both non-transient computer storage media and communication media, which include any media that facilitates a computer program to be transferred from one place to another. Non-transient storage media can be any available medium that can be accessed by a general or special-purpose computer. As an example and not limitation, non-transient computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transient medium that can be used to carry or store the desired program code means of an instruction or data structure form and can be accessed by a general or special-purpose computer, or a general or special-purpose processor. Similarly, any connection is also properly referred to as a computer-readable medium. For example, if software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of computer-readable media. Disk and disc, as used herein, include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0236] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Likewise, as used herein, the phrase "based on" should not be read as referencing a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be read in the same manner as the phrase "based at least in part on."

[0237] In the accompanying drawings, similar components or features may have the same reference number. In addition, components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between the similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, regardless of the second reference number or other subsequent reference numbers.

[0238] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that can be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” over other examples. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0239] The description herein is presented to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: identifying a propagation delay for communications between the UE and a network device via a satellite based at least in part on round-trip delay information received from a network; determining uplink timing for initiating uplink communication to the network device via the satellite based at least in part on the propagation delay and the propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a network device timing reference, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the network device; as well as transmitting the uplink communication to the network device via the satellite based at least in part on the uplink timing; The method further comprises: receiving configuration information, wherein the configuration information indicates whether the uplink timing is based on the satellite timing reference and a propagation delay from the UE to the satellite, or based on the network device timing reference and a propagation delay from the UE to the network device.

2. The method of claim 1, further comprising: determining a first portion of the propagation delay and a first propagation delay variation for a UE-to-satellite link; determining a second portion of the propagation delay and a second propagation delay variation for a satellite-to-network device link; and Wherein the propagation delay for communication between the UE and the network device is based at least in part on one or more of a first portion of the propagation delay, the first propagation delay variation, a second portion of the propagation delay, or the second propagation delay variation.

3. The method of claim 1, wherein the configuration information is provided in a system information broadcast transmission or in UE-specific signaling.

4. The method of claim 1, wherein: The configuration information indicates that the uplink timing is relative to the network device timing reference; and The configuration information further provides a round trip delay offset associated with the network device and the satellite, and a round trip delay variation associated with the network device and the satellite.

5. The method of claim 1 , wherein the configuration information indicates that the uplink timing is based on the satellite timing reference, and wherein the uplink timing is determined based solely on the UE-to-satellite propagation delay and UE-to-satellite propagation delay variation.

6. The method of claim 1, further comprising: receiving an indication of a validity time associated with the round trip delay information; as well as The validity time associated with the round-trip delay information is identified based at least in part on receiving the indication.

7. The method of claim 6, wherein the validity time begins when a system information block (SIB) containing the round-trip delay information is retrieved, and wherein monitoring updated round-trip delay information comprises retrieving another instance of the SIB.

8. The method of claim 1 , wherein the round trip delay information comprises an initial value of the propagation delay for an initial access procedure, and wherein the propagation delay change is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

9. The method of claim 1 , wherein the round-trip delay information comprises a satellite-to-network device propagation delay, and wherein the UE determines a UE-to-satellite propagation delay, and wherein the propagation delay variation is determined based on a duration over which a plurality of propagation delays are determined.

10. The method of claim 9, wherein the round trip delay information further comprises a propagation delay from the UE to a satellite.

11. The method of claim 10, wherein a midpoint of a transmission beam coverage area of ​​a transmission beam used for communication with the UE is considered as the position of the UE for a propagation delay of the UE to a satellite.

12. The method of claim 1, wherein the round-trip delay information comprises a network device-to-UE propagation delay for an initial access procedure, and wherein the propagation delay variation is determined after the initial access procedure.

13. The method of claim 1, wherein the identifying further comprises: A broadcast transmission including the round-trip delay information is received, and wherein the broadcast transmission is periodically broadcast by the network device or another network node with a first periodicity.

14. The method of claim 1, wherein the round trip delay information comprises the propagation delay and the propagation delay variation.

15. The method of claim 14, wherein the propagation delay is provided in broadcast signaling and the propagation delay variation is provided in dedicated signaling to the UE.

16. The method of claim 1 , wherein the round-trip delay information comprises an indication of the propagation delay and is periodically provided by the network device, and wherein the propagation delay variation is determined based at least in part on a difference between two or more instances of the propagation delay provided by the network device.

17. The method of claim 1, wherein the identification comprises: receiving an indication of a location of a network device in the round-trip delay information; as well as One or more of the propagation delay or the propagation delay variation is determined based at least in part on the network equipment location, the UE location, and a satellite location.

18. The method of claim 17, wherein the network device location is provided in radio resource control signaling when the UE is in a connected mode with the network device.

19. The method of claim 17, wherein the network device location is a virtual geographical location that allows the propagation delay variation to be determined and is provided in dedicated signaling to the UE or broadcast signaling from the network device.

20. A method for wireless communication at a network device, comprising: identifying round trip delay information associated with a propagation delay for communicating with at least a first user equipment (UE) via a satellite; determining, based at least in part on the round-trip delay information, configuration information indicating whether the first UE is to identify uplink timing for uplink communications to the network device via the satellite based on a satellite timing reference and a UE-to-satellite propagation delay or based on a network device timing reference and a UE-to-network device propagation delay, wherein the uplink timing is based at least in part on the propagation delay and a propagation delay variation, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the network device; as well as transmitting the configuration information to at least the first UE; as well as The round trip delay information is transmitted to the first UE.

21. The method of claim 20, wherein the configuration information is transmitted in a system information broadcast transmission from the network device or in UE-specific signaling to the first UE.

22. The method of claim 20, wherein: The configuration information indicates that the uplink timing is relative to the network device timing reference; and The configuration information further provides a round trip delay offset associated with the network device and the satellite, and a round trip delay variation associated with the network device and the satellite.

23. The method of claim 20, wherein the configuration information indicates that the uplink timing is based on the satellite timing reference, and wherein the uplink timing is determined based solely on the UE-to-satellite propagation delay.

24. The method of claim 20, further comprising: Subsequent instances of the configuration information are periodically transmitted with updated round-trip delay information.

25. The method of claim 20, wherein the round trip delay information comprises an initial value of the propagation delay for an initial access procedure, and wherein the propagation delay change is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

26. An apparatus for wireless communication at a user equipment (UE), comprising: processor, a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: identifying a propagation delay for communications between the UE and a network device via a satellite based at least in part on round-trip delay information received from a network; receiving an indication of a validity time associated with the round trip delay information; determining uplink timing for initiating uplink communication to the network device via the satellite based at least in part on the propagation delay and the propagation delay variation, wherein the uplink timing is determined relative to a satellite timing reference or a network device timing reference, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the network device; transmitting the uplink communication to the network device via the satellite based at least in part on the uplink timing; as well as monitoring updated round trip delay information in response to expiration of the validity time, The instructions are further executable by the processor to cause the apparatus to: Configuration information is received, the configuration information indicating whether the uplink timing is based on the satellite timing reference and a UE-to-satellite propagation delay or based on the network device timing reference and a UE-to-network device propagation delay.

27. The apparatus of claim 26, wherein the configuration information indicates that the uplink timing is based on the satellite timing reference, and wherein the uplink timing is determined based solely on the UE-to-satellite propagation delay and UE-to-satellite propagation delay variation.

28. The apparatus of claim 26, wherein the instructions are further executable by the processor to cause the apparatus to: determining a first portion of the propagation delay and a first propagation delay variation for a UE-to-satellite link; determining a second portion of the propagation delay and a second propagation delay variation for a satellite-to-network device link; and Wherein the propagation delay for communication between the UE and the network device is based at least in part on one or more of a first portion of the propagation delay, the first propagation delay variation, a second portion of the propagation delay, or the second propagation delay variation.

29. The apparatus of claim 26, wherein the instructions are further executable by the processor to cause the apparatus to: The validity time associated with the round-trip delay information is identified based at least in part on receiving the indication.

30. The apparatus of claim 29, wherein the validity time begins upon acquiring a system information block (SIB) containing the round-trip delay information, and wherein monitoring for updated round-trip delay information comprises acquiring another instance of the SIB.

31. The apparatus of claim 26, wherein the round-trip delay information comprises an initial value of the propagation delay for an initial access procedure, and wherein the propagation delay change is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

32. The apparatus of claim 26, wherein the round-trip delay information comprises a satellite-to-network device propagation delay, and wherein the UE determines a UE-to-satellite propagation delay, and wherein the propagation delay variation is determined based on a duration over which a plurality of propagation delays are determined.

33. The apparatus of claim 26, wherein the round-trip delay information comprises a network device-to-UE propagation delay for an initial access procedure, and wherein the propagation delay variation is determined after the initial access procedure.

34. The apparatus of claim 26, wherein the round trip delay information comprises the propagation delay and the propagation delay variation.

35. The apparatus of claim 34, wherein the propagation delay is provided in broadcast signaling and the propagation delay variation is provided in dedicated signaling to the UE.

36. The apparatus of claim 26, wherein the round-trip delay information comprises an indication of the propagation delay and is periodically provided by the network device, and wherein the propagation delay variation is determined based at least in part on a difference between two or more instances of the propagation delay provided by the network device.

37. The apparatus of claim 26, wherein for identification, the instructions are further executable by the processor to cause the apparatus to: receiving an indication of a location of a network device in the round trip delay information; and One or more of the propagation delay or the propagation delay variation is determined based at least in part on the network equipment location, the UE location, and a satellite location.

38. An apparatus for wireless communication at a network device, comprising: processor, a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: identifying round trip delay information associated with a propagation delay for communicating with at least a first user equipment (UE) via a satellite; determining, based at least in part on the round-trip delay information, configuration information indicating whether the first UE is to identify uplink timing for uplink communications to the network device via the satellite based on a satellite timing reference and a UE-to-satellite propagation delay or based on a network device timing reference and a UE-to-network device propagation delay, wherein the uplink timing is based at least in part on the propagation delay and a propagation delay variation, and wherein the propagation delay variation is based at least in part on movement of the satellite relative to the UE or movement of the satellite relative to both the UE and the network device; as well as transmitting the configuration information to at least the first UE; as well as The round trip delay information is transmitted to the first UE.

39. The apparatus of claim 38, wherein the round-trip delay information comprises an initial value of the propagation delay for an initial access procedure, and wherein the propagation delay change is determined after the initial access procedure based on a duration in which a plurality of propagation delays are determined.

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