Techniques for mobility between terrestrial and non-terrestrial networks

Abstract

Techniques are described for supporting mobility (602; 602') of a wireless device (100; 800; 1091; 1092; 1130) between a terrestrial network (TN) (210) and a non-terrestrial network (NTN) (500). With respect to a method aspect of the technique implemented by the wireless device (100; 800; 1091; 1092; 1130), a control message (520) is received from at least one TN node (200; 900; 1012a; 1012c; 1120) of the TN (210) at the wireless device (100; 800; 1091; 1092; 1130). The control message (520) instructs at least one NTN cell (512) of the NTN (500) to support mobility (602) of the wireless device (100; 800; 1091; 1092; 1130) between the TN (210) and the NTN (500).

Description

[Technical Field]

[0001] The present disclosure relates to techniques for wireless device mobility between terrestrial and non-terrestrial networks. More particularly, and without limitation, methods and devices are provided for supporting wireless device mobility between terrestrial and non-terrestrial networks. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) specified the Evolved Packet System (EPS) in 3GPP Release 8. EPS is based on a 3GPP Long-Term Evolution (LTE) based Radio Access Network (RAN) and a 3GPP Evolved Packet Core (EPC) based Core Network (CN). EPS was originally intended to provide voice and mobile broadband (MBB) services but has continuously evolved to expand its capabilities. Since 3GPP Release 13, Narrowband Internet of Things (NB-IoT) and LTE for Machine-Type Communications (MTC or LTE-M) have been part of the 3GPP specifications for LTE, providing connectivity to massive machine-type communications (mMTC) services.

[0003] 3GPP Release 15 specified the first release of the fifth-generation (5G) system (5GS). This is a new generation of radio access technology (RAT) intended to serve use cases such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and mMTC. The 5G RAT includes the New Radio (NR) access stratum (AS) interface and the 5G core network (5GC). The NR physical layer and higher layers reuse parts of the LTE specification, to which additional components are added, for example, for non-LTE use cases. One such component is the introduction of a high-performance framework for beamforming and beam management to extend support for 3GPP technology beyond 6 GHz.

[0004] In Release 15, 3GPP started work to prepare NR for operation in non-terrestrial networks (NTN). That work was done, for example, in the study item "NR to support Non-Terrestrial Networks" according to 3GPP document RP-193234. In Release 16, work to prepare NR for operation in NTN networks continued in the study item "Solutions for NR to support Non-Terrestrial Network." In parallel, there is growing interest in adapting NB-IoT and LTE-M for operation in NTN. As a result, 3GPP Release 17 includes work items for both NR NTN and NB-IoT and LTE-M support for NTN.

[0005] However, there is currently limited support for achieving service continuity for wireless devices handed over from a terrestrial 3GPP network (TN) to connect to a 3GPP NTN, which can result in degraded end-user performance. Summary of the Invention

[0006] Therefore, there is a need for techniques that support mobility between terrestrial and non-terrestrial networks.

[0007] Regarding a first method aspect, there is provided a method for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN), as set forth in claim 1. The method, implemented by the wireless device, includes or initiates receiving at least one of a control message from at least one TN node of the TN at the wireless device and a control message from at least one NTN node of the NTN at the wireless device. The control message from the at least one TN node indicates at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN. The control message from the at least one NTN node indicates at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0008] The first method aspect may be performed by a wireless device.

[0009] By receiving a control message from at least one TN node of the TN, at least some embodiments of a wireless device may be supported in (e.g., may be assisted in, and / or prepared for, and / or configured for) mobility between a TN and an NTN, e.g., from a TN to an NTN. The same or additional embodiments of a wireless device may be supported in (e.g., may be assisted in, and / or prepared for, and / or configured for) mobility between a TN and an NTN, e.g., from an NTN to a TN, by receiving a control message from at least one NTN node of the NTN.

[0010] For example, the present technique may be implemented in accordance with 3GPP and / or in the evolution of the NTN in Release 18. At least some embodiments of the present technique may enable NTN connectivity (i.e., wireless access) provided by the NTN to complement terrestrial network connectivity (i.e., wireless access provided by the TN). One example is that the NTN may provide coverage over areas where coverage by the TN is absent. For example, the present technique may be specified in 3GPP Release 18 to address service continuity between connectivity provided by the NTN and connectivity provided by the TN.

[0011] In at least some embodiments, the control messages may support mobility of wireless devices between the TN and the NTN. For example, the control messages may assist wireless devices in (e.g., during) handover from the TN to the NTN and / or from the NTN to the TN.

[0012] A TN may refer to a radio access network (RAN) or a segment of a RAN that uses one or more terrestrial (e.g., ground-based and / or stationary) network nodes (TN nodes, e.g., TN base stations). The one or more TN nodes may comprise one or more network nodes located on and / or supported by the surface of Earth, Mars, or any other planet.

[0013] At least one NTN node may comprise one or more airborne vehicles and / or one or more spaceborne vehicles.

[0014] An NTN may refer to a RAN or a segment of a RAN that uses one or more non-terrestrial vehicles as non-terrestrial network nodes (NTN nodes, e.g., NTN base stations) for, for example, radio transmission, radio reception, and / or radio access. The non-terrestrial radio access vehicles may comprise one or more airborne vehicles and / or one or more spaceborne vehicles. As used herein, airborne may refer to the atmosphere (e.g., including but not limited to air) of the respective planet. Airborne may mean supported by and / or in the atmosphere. Alternatively or additionally, spaceborne may mean moving according to celestial mechanics and / or being in space (e.g., outer space).

[0015] The airborne vehicle may comprise one or more High Altitude Platforms (HAPs), such as Unmanned Aircraft Systems (UASs), optionally including tethered UASs, Lighter than Air UASs, and Heavier than Air UASs. HAPs may operate at altitudes between 8 km and 50 km and / or quasi-geostationary.

[0016] A spaceborne (also written space-borne) vehicle may comprise one or more satellites, e.g., any device in orbit around a respective planet. A spaceborne vehicle may be in low Earth orbit (LEO), medium Earth orbit (MEO), or geostationary Earth orbit (GEO).

[0017] The TN and NTN may be segments of a RAN. Alternatively or additionally, a feeder link (also referred to as a wireless access link) may wirelessly connect the NTN (e.g., at least one NTN node) and the TN (e.g., to at least one TN node). Alternatively, the TN and NTN may be two RANs connected to the same core network (CN). For example, a feeder link may connect the CN and the NTN.

[0018] A TN (e.g., one or each of at least one TN node) may be configured, for example, to serve wireless devices (i.e., provide wireless access to wireless devices) in one or more TN cells. This may also be referred to as at least one TN node serving one or more TN cells. Alternatively or additionally, an NTN (e.g., one or each of at least one NTN node of an NTN) may be configured, for example, to serve wireless devices (i.e., provide wireless access to wireless devices) in one or more NTN cells. This may also be referred to as at least one NTN node serving one or more NTN cells. Each cell of the TN and / or each cell of the NTN may correspond to a coverage area (e.g., on the surface of the respective planet). Optionally, the coverage area of ​​at least one or each NTN cell of the NTN nodes may be movably controlled (e.g., steerable) by the respective NTN node.

[0019] Mobility between a TN and an NTN may include a wireless device moving from a TN cell of a TN to an NTN cell of an NTN, or from an NTN cell of an NTN to a TN cell of a TN.

[0020] Alternatively or additionally, mobility may include the wireless device selecting (e.g., reselecting) an NTN cell of the NTN in an idle state of the wireless device, and optionally, the selected (e.g., reselected) NTN cell is an NTN cell of at least one NTN node. Alternatively or additionally, mobility may include the wireless device initiating a connection resumption procedure (e.g., sending an RRC connection resume) in an inactive state of the wireless device, and optionally, the connection resume is sent to at least one NTN node serving at least one NTN cell. Alternatively or additionally, mobility may include the wireless device performing a location update procedure that enables the wireless device to update the TN and / or NTN allocated to the wireless device. Alternatively or additionally, mobility may include a wireless device being handed over from at least one TN node (or from a TN cell of at least one TN node) to at least one NTN node (or to at least one NTN cell), or being handed over from at least one NTN node (or from at least one NTN cell) to at least one TN node (or to a TN cell of at least one TN node).

[0021] At least one TN node of the TN (e.g., according to the first method aspect) may provide wireless access in at least one TN cell. Alternatively or additionally, at least one NTN node of the NTN may provide wireless access in at least one NTN cell. Alternatively or additionally, the control message may include a location of the or each of the at least one NTN node, a velocity of the or each of the at least one NTN node, a trajectory of the or each of the at least one NTN node, a coverage area covered by the or each of the at least one NTN node, optionally at least one of a reference point of the coverage area, a center of the coverage area, and a size of the coverage area, a coverage area covered by the or each of the at least one NTN cell, optionally at least one of a reference point of the coverage area, a center of the coverage area, and a size of the coverage area, a cell identifier, cell ID, and / or carrier frequency of the or each of the at least one NTN node or the at least one NTN cell, and a carrier frequency of the or each of the at least one NTN node or the at least one NTN cell. The command may include a handover command for handover of the wireless device from the at least one NTN node or at least one TN cell to the at least one NTN node or at least one NTN cell, a handover command for handover of the wireless device from the at least one NTN node or at least one NTN cell to the at least one TN node or at least one TN cell, and optionally indicate at least one of: a position of the wireless device relative to the at least one NTN node; an elevation angle and / or an azimuth angle for uplink transmission from the wireless device to the at least one NTN node and / or downlink reception at the wireless device from the at least one NTN node; a timing advance (TA) or TA pre-compensation for uplink transmission from the wireless device to the at least one NTN node; and a precoder for beamformed transmission from the wireless device to the at least one NTN node.

[0022] The wireless device may receive the control message in a serving TN cell of the TN, and / or the at least one TN node may be or comprise the serving TN node of the wireless device.

[0023] The trajectory (e.g., flight path or orbit) of each NTN node is sometimes referred to as ephemeris (or plural: ephemerides) or ephemeris data, i.e., data that may indicate the trajectory of each airborne or spaceborne vehicle embodying the NTN node. Alternatively or additionally, the control messages may indicate, for example, at least one of the position and velocity of each NTN node over time (e.g., at periodic points in time).

[0024] A coverage area covered by one or each of the at least one NTN node may be an area (e.g., on the surface of a respective planet) to which the respective NTN node is configured to provide wireless access. In other words, the NTN node can provide wireless access when a wireless device is within the coverage area. The coverage area of ​​each NTN node may also be referred to as the NTN cell (e.g., beam spot) of the respective NTN node. Furthermore, the terms NTN cell and NTN node may be used interchangeably. For example, transmission or reception in an NTN cell may refer to transmission to or reception from the NTN node serving the respective NTN cell.

[0025] One or each of the at least one NTN cell may be a target cell of mobility (e.g., handover). Alternatively or additionally, one or each of the at least one NTN node may be a target node of mobility (e.g., handover). Alternatively or additionally, one or each of the at least one TN cell may be a source cell of mobility (e.g., handover). Alternatively or additionally, one or each of the at least one TN node may be a source node of mobility (e.g., handover).

[0026] The wireless device may calculate at least one of a TA, a pre-compensation (e.g., a course estimate) for the TA, a precoder, an elevation angle, and an azimuth angle based on the control message (e.g., for uplink transmission from the wireless device to at least one NTN node and / or downlink reception from at least one NTN node to the wireless device).

[0027] At least one TN cell may be serving the wireless device (e.g., according to the first method aspect). Alternatively or additionally, the at least one TN node may be a serving node of the wireless device. Alternatively or additionally, the at least one TN cell and the at least one NTN cell are adjacent or overlapping cells.

[0028] The TN cell (e.g., the serving TN cell) of the at least one TN node and one or each of the at least one NTN cell may be adjacent or overlapping cells.

[0029] At least one TN cell (e.g., according to the first method aspect) may be a source cell of the mobility. Alternatively or additionally, at least one TN node may be a source node of the mobility. Alternatively or additionally, at least one NTN cell may be a target cell of the mobility. Alternatively or additionally, at least one NTN node may be a target node of the mobility.

[0030] The method (e.g., according to a first method aspect) may further include or initiate at least one of: measuring radio signal strength (RSS) of at least one NTN node or at least one NTN cell and reporting the measured RSS in a control message upon request; pointing a directional antenna of the wireless device toward the at least one NTN node in accordance with the control message or applying a precoder to multiple antennas of the wireless device to point a radio beam toward the at least one NTN node in accordance with the control message; establishing or resuming a connection with the at least one NTN node or at least one NTN cell in accordance with the control message; transmitting a random access preamble from the wireless device to the at least one NTN node or at least one NTN cell in accordance with the control message; and performing a handover of the wireless device from the at least one TN node or at least one TN cell to the at least one NTN node or at least one NTN cell in accordance with the control message.

[0031] The RSS of at least one NTN node or NTN cell may be measured, and / or the measured RSS may be reported in a control message only upon request. Alternatively or additionally, the wireless device may refrain from measuring the RSS of at least one NTN node or NTN cell and / or from reporting the measured RSS if the RSS of the TN (e.g., of at least one TN node or TN cell) is equal to or greater than a predefined TN threshold, e.g., if the RSS of the TN is adequate or sufficient for a connection between the wireless device and the at least one TN node or TN cell.

[0032] As used herein, the RSS may be or include at least one of a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal-to-noise ratio (SNR), a signal-to-interference ratio (SIR), and a signal-to-interference-and-noise ratio (SINR). Alternatively or additionally, measuring the RSS of the at least one NTN node or NTN cell may be based on at least one of a reference signal (RS) or a synchronization signal (e.g., a synchronization signal block (SSB), i.e., a synchronization and physical broadcast channel (PBCH) block) of the at least one NTN node or NTN cell.

[0033] The multiple antennas may be referred to as an antenna system, e.g., a multiple-input multiple-output (MIMO) antenna system. Pointing the directional antenna may include, for example, rotating the directional antenna so that a maximum of the radiation characteristic of the directional antenna is aimed at at least one NTN node. Alternatively or additionally, pointing the radio beam may include, for example, pointing a beamformed transmission (i.e., pointing a maximum transmit gain) and / or pointing a beamformed reception (i.e., pointing a maximum receive gain) to at least one NTN node. The precoder may include beamforming weights (e.g., complex numbers) for each of the multiple antennas.

[0034] The connection may be established or resumed when leaving the coverage area of ​​the TN and / or when entering the coverage area of ​​the NTN.

[0035] Establishing or resuming a connection may include transmitting a random access preamble.

[0036] A wireless device (e.g., according to a first method aspect) may perform at least one of the steps of claim 7 upon fulfillment of a condition. Alternatively or additionally, the control message may indicate the condition. The condition may include at least one of: leaving a coverage area of ​​at least one TN node; leaving at least one TN cell; entering a coverage area of ​​at least one NTN node; entering at least one NTN cell; measuring an RSS of at least one TN node or at least one TN cell equal to or less than a predefined TN RSS threshold; measuring an RSS or RSS of at least one NTN node or at least one NTN cell equal to or greater than a predefined RSS NTN threshold; and measuring an RSS or RSS of at least one NTN node or at least one NTN cell greater than the RSS of the at least one TN node or at least one TN cell, optionally by a predefined hysteresis offset.

[0037] The fulfillment of a condition may also be referred to as a trigger. Alternatively or additionally, the condition may be a predefined condition for mobility (e.g., handover) from a TN to an NTN or from an NTN to a TN.

[0038] As used herein, "predefined" may include "configured" (e.g., by control message or separate configuration message, optionally from at least one TN node) and / or "specified" (e.g., in a technical specification and / or hard-coded).

[0039] The control message (e.g., according to the first method aspect) may optionally be broadcast in the system information (SI) of at least one TN node or at least one TN cell. Alternatively or additionally, the control message may optionally be unicast to wireless devices in the radio resource control (RRC) signaling of at least one TN node or at least one TN cell.

[0040] The method (e.g., according to the first method aspect) may further include or initiate receiving SI from at least one TN node. The SI may support mobility of wireless devices between the TN and the NTN and / or indicate availability of information regarding the NTN. The method may further include or initiate sending a request to the at least one TN node based on the indication in the SI. A control message may be received in response to the sent request.

[0041] The method (e.g., according to the first method aspect) may further include or initiate searching for an NTN cell of the NTN for a predefined time period, and if the NTN cell of the NTN is not found within the predefined time period, sending a request to at least one TN node. A control message may be received in response to the sent request.

[0042] At least one TN node of the TN (e.g., according to the first method aspect) may provide wireless access in at least one TN cell. Alternatively or additionally, at least one NTN node of the NTN may provide wireless access in at least one NTN cell. The control message may include the location of the or each of the at least one TN node, a coverage area covered by the or each of the at least one TN node, optionally at least one of a reference point for the coverage area, a center of the coverage area, and a size of the coverage area, a coverage area covered by the or each of the at least one TN cell, optionally at least one of a reference point for the coverage area, a center of the coverage area, and a size of the coverage area, a cell identifier (cell ID) and / or carrier frequency of the or each of the at least one TN node or one of the at least one TN cell, and a location from the at least one NTN node or at least one NTN cell to the at least one TN node or at least one NTN cell. The command may include a handover command for handover of the wireless device to at least one TN cell, a handover command for handover of the wireless device from at least one TN node or at least one TN cell to at least one NTN node or at least one NTN cell, and optionally indicate at least one of the following relative to the at least one TN node: a position of the wireless device; an elevation angle and / or an azimuth angle for uplink transmission from the wireless device to the at least one TN node and / or downlink reception at the wireless device from the at least one TN node; a timing advance (TA) or TA pre-compensation for uplink transmission from the wireless device to the at least one TN node; and a precoder for beamformed transmission from the wireless device to the at least one TN node.

[0043] At least one NTN cell may be serving the wireless device (e.g., according to the first method aspect). Alternatively or additionally, the at least one NTN node may be a serving node of the wireless device. Alternatively or additionally, the at least one TN node and the at least one NTN node are neighboring nodes, optionally next-neighboring nodes.

[0044] At least one TN cell (e.g., according to the first method aspect) may be a target cell of the mobility. Alternatively or additionally, at least one TN node may be a target node of the mobility. Alternatively or additionally, at least one NTN cell may be a source cell of the mobility. Alternatively or additionally, at least one NTN node may be a source node of the mobility.

[0045] The method (e.g., according to a first method aspect) may further include or initiate at least one of: measuring radio signal strength (RSS) of at least one TN node or at least one TN cell and reporting the measured RSS in a control message upon request; pointing a directional antenna of the wireless device toward the at least one TN node in accordance with the control message or applying a precoder to multiple antennas of the wireless device to point a radio beam toward the at least one TN node in accordance with the control message; establishing or resuming a connection with the at least one TN node or at least one TN cell in accordance with the control message; transmitting a random access preamble from the wireless device to the at least one TN node or at least one TN cell in accordance with the control message; and performing a handover of the wireless device from the at least one NTN node or at least one NTN cell to the at least one TN node or at least one TN cell in accordance with the control message.

[0046] A wireless device (e.g., according to a first method aspect) may perform at least one of the steps of claim 15 upon fulfillment of a condition. Alternatively or additionally, the control message may indicate the condition, and / or the condition may include at least one of: leaving a coverage area of ​​at least one NTN node, leaving at least one NTN cell, entering a coverage area of ​​at least one TN node, entering at least one TN cell, measuring an RSS of the at least one NTN node or at least one NTN cell that is equal to or less than a predefined NTN RSS threshold, measuring an RSS of the at least one TN node or at least one TN cell that is equal to or greater than a predefined RSS TN threshold, and measuring an RSS of the at least one TN node or at least one TN cell that is greater than the RSS of the at least one NTN node or at least one NTN cell, optionally by a predefined hysteresis offset.

[0047] The control message (e.g., according to the first method aspect) may optionally be broadcast in the system information (SI) of at least one TN node or at least one TN cell. Alternatively or additionally, the control message may optionally be unicast to wireless devices in the radio resource control (RRC) signaling of at least one TN node or at least one TN cell.

[0048] The method (e.g., according to a first method aspect) may further include or commence receiving SI from at least one NTN node, the SI supporting wireless device mobility between the TN and the NTN and / or indicating availability of information regarding the TN. The method may further include or commence sending a request to the at least one NTN node based on the indication in the SI. A control message may be received in response to the sent request.

[0049] The method (e.g., according to the first method aspect) may further include or initiate searching for a TN cell of the TN for a predefined time period. If a TN cell of the TN is not found within the predefined time period, transmitting a request to at least one NTN node. A control message may be received in response to the transmitted request.

[0050] With respect to a second method aspect, there is provided a method for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) as set forth in claim 20. The method is performed by at least one TN node of the TN. The method includes or initiates a step of transmitting a control message from the at least one TN node to the wireless device, the control message indicating at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN.

[0051] The second method aspect may be implemented by at least a TN node of a TN.

[0052] The second method aspect may further include any feature and / or any step disclosed in the context of the first method aspect, or corresponding features and / or steps, e.g., receiver counterparts or TN counterparts to transmitter or wireless device features or steps.

[0053] With respect to a third method aspect, there is provided a method for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) as set forth in claim 22. The method is performed by at least one NTN node of the NTN. The method includes or initiates a step of transmitting a control message from the at least one NTN node to the wireless device, the control message indicating at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0054] The third method aspect may be performed by at least one NTN node of an NTN.

[0055] The third method aspect may further include any feature and / or any step disclosed in the context of the first and / or second method aspects, or corresponding features and / or steps, e.g., receiver counterparts or NTN counterparts to transmitter or wireless device features or steps.

[0056] In another aspect, a computer program product is provided. The computer program product includes program code portions for performing any one of the steps of the first, second, and / or third method aspects disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for downloading, for example, via a wireless network, a RAN, the Internet, and / or a host computer. Alternatively, or in addition, the method may be coded in a field programmable gate array (FPGA) and / or an application-specific integrated circuit (ASIC), or functions may be provided for downloading by a hardware description language.

[0057]

[0013] Regarding a first device aspect, a wireless device for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided. The wireless device comprises a memory operable to store instructions and a processing circuit operable to execute the instructions, such that the wireless device is operable to receive at least one of a control message from at least one TN node of the TN at the wireless device, where the control message indicates at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN, and a control message from at least one NTN node of the NTN at the wireless device, where the control message indicates at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0058] The wireless device (eg, according to the first device aspect) may be further operable to perform any one of the steps of the first method aspect.

[0059] According to another first device aspect, a wireless device for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided, wherein the wireless device is configured to receive at least one of a control message from at least one TN node of the TN at the wireless device, the control message indicating at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN, and a control message from at least one NTN node of the NTN at the wireless device, the control message indicating at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0060] The wireless device (eg, according to the first device aspect) may be further configured to perform any one of the steps of the first method aspect.

[0061] Regarding another first device aspect, a user equipment (UE) for supporting UE mobility between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided. The UE is configured to communicate with both a TN node of the TN and an NTN node of the NTN, the UE comprising a radio interface and a processing circuit, the processing circuit configured to receive at least one of a control message from at least one TN node of the TN at the wireless device, the control message indicating at least one NTN cell of the NTN for supporting the wireless device mobility between the TN and the NTN, and a control message from at least one NTN node of the NTN at the wireless device, the control message indicating at least one TN cell of the TN for supporting the wireless device mobility between the TN and the NTN.

[0062] In a UE (eg, according to the first device aspect), the processing circuitry may be further configured to perform any one of the steps of the first method aspect.

[0063] With respect to a second device aspect, a terrestrial network node (TN) node for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided, the TN node comprising a memory operable to store instructions and a processing circuit operable to execute the instructions, such that the TN node is operable to: transmit a control message from the TN node to a wireless device, the control message indicating at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN.

[0064] The TN node (eg, according to the second device aspect) may be further operable to perform any one of the steps of the second method aspect.

[0065] Regarding another second device aspect, a terrestrial network node (TN node) for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided, wherein the TN node is configured to: transmit a control message from the TN node to the wireless device, the control message indicating at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN.

[0066] The TN node (eg, according to the second device aspect) may be further configured to perform any one of the steps of the second method aspect.

[0067] With respect to a third device aspect, a non-terrestrial network node (NTN) node is provided for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN). The NTN node comprises a memory operable to store instructions and a processing circuit operable to execute the instructions, such that the NTN node is operable to: transmit a control message from at least one NTN node to a wireless device, the control message indicating at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0068] An NTN node (e.g., according to the third device aspect) may be further operable to perform any one of the steps of the third method aspect.

[0069]

[0013] Regarding another third device aspect, a non-terrestrial network node (NTN) node for supporting mobility of a wireless device between a terrestrial network (TN) and a non-terrestrial network (NTN) is provided, wherein the NTN node is configured to: transmit a control message from at least one NTN node to the wireless device, the control message indicating at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN.

[0070] The NTN node (e.g., according to the third device aspect) may be further configured to perform any one of the steps of the third method aspect.

[0071] With respect to a system aspect, a communications system is provided, the communications system including a host computer having processing circuitry configured to provide user data and a communications interface configured to forward the user data to a terrestrial network (TN) or a non-terrestrial network for transmission to a user equipment (UE), the UE having a wireless interface and processing circuitry, the processing circuitry of the UE being configured to perform any one of the steps of the first method aspect.

[0072] The communications system (eg, according to system aspects) may further include a UE.

[0073] The TN and NTN (e.g., according to system aspects) may further comprise a TN node and an NTN node, each of which is configured to communicate with the UE.

[0074] Each of the TN and NTN (e.g., according to a system aspect) may comprise processing circuitry, the processing circuitry being configured to perform any one of the steps of the second method aspect and the steps of the third method aspect, respectively.

[0075] The processing circuitry of the host computer (e.g., according to a system aspect) may be configured to execute a host application and thereby provide user data, and the processing circuitry of the UE may be configured to execute a client application associated with the host application.

[0076] For example, without limitation, in a 3GPP implementation, any "wireless device" may be user equipment (UE). Any one of the method aspects may be embodied by a method for supporting terrestrial-to-non-terrestrial network service continuity.

[0077] Embodiments of the present technique may be implemented for at least one of 5G NR, NB-IoT, LTE-M, NTN, satellite communications, and service continuity.

[0078] The techniques may be applied in the context of 3GPP New Radio (NR), for example, in the implementation of one or more quality of service (QoS) levels.

[0079] The techniques may be implemented in accordance with 3GPP specifications, e.g., for 3GPP Release 17 or 18. The techniques may be implemented for 3GPP LTE or 3GPP NR, e.g., according to 3GPP document TS38.331, version 16.6.0, as modified. For example, the control messages may be implemented using or modifying radio resource control (RRC) signaling specified in 3GPP document TS38.331 for NR.

[0080] The wireless device may receive multiple instances of the control message. For example, a first instance of the control message may include an indication of support for at least one TN node signaling NTN information to the wireless device in a second instance of the control message (e.g., upon request). Alternatively or additionally, different instances of the control message may be received from different TN nodes (of the at least one TN node), or from different NTN nodes (of the at least one NTN node), or from at least one TN node and at least one NTN node.

[0081] The wireless device may be, for example, a user equipment (UE) according to 3GPP specifications. Alternatively or additionally, at least one NTN node may be a satellite or spaceborne base station. Alternatively or additionally, the TN node may be a stationary and / or terrestrial (e.g., land-based) base station.

[0082] To serve the wireless device, the wireless device may be wirelessly connected to at least one TN node and / or at least one NTN in an uplink (UL) and / or downlink (DL) over a Uu interface. Alternatively or additionally, the wireless connection between the at least one NTN node and the wireless device may use the Ku microwave band and the Ka microwave band, which operate in the 12-18 GHz and 26.5-49 GHz bands, respectively.

[0083] The RANs, i.e., the TN and NTN, may comprise one or more base stations that implement the second and third method aspects, respectively.

[0084] Any of the wireless devices may be 3GPP user equipment (UE) or a Wi-Fi station (STA) or a subscriber ground station. The wireless device may be a mobile station or a portable station, a device for machine-type communications (MTC), a device for narrowband Internet of Things (NB-IoT), or a combination thereof. Examples of UEs and mobile stations include mobile phones, tablet computers, and autonomous vehicles. Examples of portable stations include laptop computers and television sets. Examples of MTC or NB-IoT devices include robots, sensors, and / or actuators in, for example, manufacturing, automotive communications, and home automation. MTC or NB-IoT devices may be implemented in manufacturing plants, household appliances, and consumer electronics.

[0085] Whenever referring to a RAN, TN, and / or NTN, it may be implemented by one or more base stations acting as TN nodes and NTN nodes.

[0086] As used herein, being wirelessly connected, or establishing a connection, or resuming a connection, or serving a wireless device may refer to the wireless device being optionally connected with at least one base station of the RAN according to a radio resource control (RRC) state or active mode.

[0087] A base station (i.e., any NT node and / or any NTN node) may encompass any station configured to provide wireless access to one or more embodiments of a wireless device. A base station (i.e., any NT node and / or any NTN node) may also be referred to as a cell, a transmit and receive point (TRP), a wireless access node, or an access point (AP). A base station and / or a wireless device may provide a data link to a host computer that provides user data to or collects user data from the wireless device. Examples for a base station (i.e., any NT node and / or any NTN node) may include a 3G base station or Node B (NB), a 4G base station or eNode B (eNB), a 5G base station or gNode B (gNB), a Wi-Fi AP, and a network controller (e.g., via Bluetooth, ZigBee, or Z-Wave).

[0088] The RAN (e.g., the TN and / or the NTN) may be implemented in accordance with Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE), and / or 3GPP New Radio (NR).

[0089] Any aspect of the present technique may be implemented on a physical layer (PHY), a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and / or a radio resource control (RRC) layer of a protocol stack for wireless communication.

[0090] As used herein, a reference to a protocol of a layer may also refer to the corresponding layer in a protocol stack, and vice versa; a reference to a layer of a protocol stack may also refer to the corresponding protocol of the layer. Any protocol may be implemented by a corresponding method.

[0091] In any aspect, the control message may include different types of TN signaling to prepare a wireless device (e.g., a UE) for efficient transfer from TN connectivity to NTN connectivity and / or from NTN connectivity to TN connectivity.

[0092] Alternatively or additionally, in any aspect, the control message may include 3GPP TN signaling of 3GPP NTN information to facilitate mobility (e.g., handover) from TN connectivity to NTN connectivity and / or from NTN connectivity to TN connectivity.

[0093] The at least one TN node may be one or more TN nodes. The at least one NTN node may be one or more NTN nodes.

[0094]

[0010] In accordance with yet a further aspect, a communications system is provided that includes a host computer. The host computer comprises processing circuitry configured to provide user data. The host computer further comprises a communications interface configured to forward the data to a cellular network (e.g., any of a RAN, TN, NTN, base station, at least one TN node, and / or at least one NTN node) for transmission to the UE. The processing circuitry of the cellular network is configured to perform any one of the steps of the second and / or third method aspects. The UE comprises a wireless interface and processing circuitry, the processing circuitry being configured to perform any one of the steps of the first method aspect.

[0095] The communication system may further include a UE. Alternatively, or in addition, the cellular network may further include one or more base stations configured for wireless communication with the UE and / or to provide a data link between the UE and a host computer using the first and / or second and / or third method aspects.

[0096] The processing circuitry of the host computer may be configured to execute a host application, thereby providing data and / or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the UE may be configured to execute a client application associated with the host application.

[0097] Any one of the device, wireless device, UE, base station, TN node, NTN node, communication system, or any node or station for embodying the present technique may further include any feature disclosed in the context of the method aspects, and vice versa. In particular, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspects.

[0098] Further details of embodiments of the present technique will be described with reference to the enclosed drawings. [Brief explanation of the drawings]

[0099] [Figure 1] FIG. 1 is a schematic block diagram of an embodiment of a device for supporting mobility of a wireless device between a TN and an NTN, which may be implementable in the wireless device. [Figure 2-1] FIG. 1 is a schematic block diagram of an embodiment of a device for supporting mobility of wireless devices between a TN and an NTN, which may be implementable in a TN. [Figure 2-2]FIG. 1 is a schematic block diagram of an embodiment of a device for supporting mobility of wireless devices between a TN and an NTN, which may be implementable in the NTN. [Figure 3] 2 is a flowchart for a method of supporting mobility of a wireless device between a TN and an NTN that may be implementable by the device of FIG. 1. [Figure 4-1] 2-1 is a flowchart for a method of supporting mobility of a wireless device between a TN and an NTN, which may be implementable by the device of FIG. 2-1. [Figure 4-2] 4 is a flowchart for a method of supporting mobility of a wireless device between a TN and an NTN that may be implementable by the device of FIG. 3. [Figure 5] 1A-1C are schematic diagrams illustrating an example of an NTN including the device embodiments of FIGS. 1, 2-1, and 2-2 for implementing the methods of FIGS. 3, 4-1, and 4-2, respectively. [Figure 6A] 1 and 2-1 for implementing the methods of FIGS. 3 and 4-1, respectively. [Figure 6B] 1 and 2-1 implementing the methods of FIGS. 3 and 4-1, respectively, in wireless communication. [Figure 7A] 1 and 2-2 for implementing the methods of FIGS. 3 and 4-2, respectively. [Figure 7B] 1 and 2-2, respectively, implementing the methods of FIGS. 3 and 4-2 in wireless communication. [Figure 8] 2 is a schematic block diagram of a wireless device embodying the device of FIG. 1; [Figure 9-1] FIG. 2-2 is a schematic block diagram of a TN node embodying the device of FIG. 2-1. [Figure 9-2] FIG. 2-3 is a schematic block diagram of an NTN node embodying the device of FIG. 2-2. [Figure 10] FIG. 1 is a schematic diagram illustrating an exemplary communication network connected to a host computer through an intermediate network. [Figure 11] FIG. 1 is a generalized block diagram of a host computer communicating with user equipment via a wireless device acting as a base station or gateway over a partially wireless connection. [Figure 12] 1 is a flowchart for a method implemented in a communication system including a host computer, a wireless device acting as a base station or gateway, and user equipment. [Figure 13] 1 is a flowchart for a method implemented in a communication system including a host computer, a wireless device acting as a base station or gateway, and user equipment. DETAILED DESCRIPTION OF THE INVENTION

[0100] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a particular network environment, to provide a thorough understanding of the techniques disclosed herein. It will be apparent to those skilled in the art that the present techniques may be practiced in other embodiments that deviate from these specific details. Moreover, while the following embodiments are primarily described for New Radio (NR) or 5G implementations, it is readily apparent that the techniques described herein may also be implemented for any other wireless communication technique, including a wireless local area network (WLAN) implementation according to the IEEE 802.11 family of standards, 3GPP LTE (e.g., LTE Advanced, or related radio access techniques such as MultiFire), for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth low energy, Bluetooth mesh networking, and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance, or for ZigBee based on IEEE 802.15.4.

[0101] Furthermore, those skilled in the art will appreciate that the functions, steps, units, and modules described herein may be implemented using software operating in conjunction with a programmed microprocessor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), or a general-purpose computer, including, for example, an advanced RISC machine (ARM). Although the following embodiments are described primarily in the context of involving methods and devices, it will be appreciated that the present invention may also be embodied in a computer program product, as well as in a system comprising at least one computer processor and a memory coupled to the at least one processor, the memory encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

[0102] 1 illustrates a block diagram of an embodiment of a device for supporting wireless device mobility between a terrestrial network (TN) and a non-terrestrial network (NTN), and / or according to a first device aspect. The devices are generally referred to by the reference numeral 100.

[0103] The device 100 comprises a control message receiving module 102 that receives at least one control message.

[0104] At least one control message may be received at the wireless device from at least one (e.g., a) TN node of the TN, the latter control message may indicate at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN, e.g., from the TN to the NTN.

[0105] Alternatively or additionally, at least one control message may be received at the wireless device from at least one (e.g., a) NTN node of the NTN, the latter control message may indicate at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN, e.g., from the NTN to the TN.

[0106] Optionally, the device 100 comprises a measurement reporting module 104 that measures the radio signal strength (RSS) of at least one NTN node and / or at least one NTN cell and / or reports the measured RSS to the TN or NTN, for example, in a control message upon request.

[0107] Alternatively or additionally, the device 100 comprises a connection establishment module that establishes or resumes a connection with at least one NTN node and / or at least one NTN cell, and / or at least one TN node and / or at least one TN cell according to the control message.

[0108] Any of the modules of device 100 may be implemented by a unit configured to provide the corresponding functionality.

[0109] The device 100 may also be referred to as or embodied by a wireless device (or, briefly, a UE).

[0110] The wireless device 100 and at least one TN node may be in direct wireless communication, for example, at least upon receiving the control message and prior to establishing or resuming the connection. The wireless device 100 and at least one NTN node may be in direct wireless communication, for example, as a result of or after establishing or resuming the connection.

[0111] Alternatively or additionally, the wireless device 100 and at least one NTN node may be in direct wireless communication, e.g., at least upon receiving the control message and prior to establishing or resuming the connection. The wireless device 100 and at least one TN node may be in direct wireless communication, e.g., as a result of or after establishing or resuming the connection.

[0112] At least one TN node may be embodied by the following device 200: At least one NTN node may be embodied by the further following device 200':

[0113] 2-1 illustrates a block diagram of an embodiment of a device for supporting wireless device mobility between a terrestrial network (TN) and a non-terrestrial network (NTN) and / or according to a second device aspect. The devices are generally referred to by the reference numeral 200.

[0114] The device 200 comprises a control transmission module 202 that transmits control messages, eg, as described in the context of the first and / or second (eg, method or device) aspects.

[0115] Any of the modules of device 200 may be implemented by a unit configured to provide the corresponding functionality.

[0116] The device 200 may also be referred to as or embodied by a TN node (or briefly, a gNB).

[0117] 2-2 illustrates a block diagram of an embodiment of a device for supporting mobility of wireless devices between a terrestrial network (TN) and a non-terrestrial network (NTN) and / or according to a third device aspect, the devices being generally referred to by the reference numeral 200′.

[0118] The device 200' comprises a control transmission module 202' that transmits control messages, eg, as described in the context of the first and / or third (eg, method or device) aspects.

[0119] Any of the modules of device 200 may be implemented by a unit configured to provide the corresponding functionality.

[0120] The device 200' may also be referred to as or embodied by an NTN node (or briefly, a satellite or HAP).

[0121] FIG. 3 shows an exemplary flowchart for a method 300 for implementing an embodiment of the first method aspect.

[0122] In step 302, the wireless device: - a control message from at least one TN node of the TN at the wireless device, the control message indicating at least one NTN cell of the NTN for supporting mobility of the wireless device between the TN and the NTN; a control message from at least one NTN node of the NTN at the wireless device, the control message indicating at least one TN cell of the TN for supporting mobility of the wireless device between the TN and the NTN; and receive at least one of

[0123] Method 300 may be performed by device 100. For example, modules 102, 104, and 106 may perform steps 302, 304, and 306, respectively.

[0124] FIG. 4-1 shows an exemplary flowchart for a method 400 for implementing one embodiment of the second method aspect.

[0125] In step 402, one or at least one TN node transmits a control message to the wireless device. The control message indicates at least one NTN cell of the NTN to support mobility of the wireless device between the TN and the NTN.

[0126] The method 400 may be performed by the device 200. For example, the module 202 may perform the step 402.

[0127] FIG. 4-2 shows an exemplary flowchart for a method 400' implementing one embodiment of the third method aspect.

[0128] In step 402′, one or at least one NTN node transmits a control message to the wireless device, the control message indicating at least one TN cell of the TN to support mobility of the wireless device between the TN and the NTN.

[0129] The method 400′ may be performed by the device 200′. For example, the module 202 may perform the step 402.

[0130] In any aspect, device 100 may be a wireless device. TN node 200 may be a terrestrial base station. NTN node 200' may be a non-terrestrial base station (e.g., satellite or HAP).

[0131] As used herein, any wireless device may be a mobile or portable station and / or any wireless device capable of wirelessly connecting to a base station or a RAN (e.g., a TN and / or NTN). For example, a wireless device may be a user equipment (UE), a device for machine-type communications (MTC), or a device for the (e.g., narrowband) Internet of Things (IoT). Two or more wireless devices may be configured to wirelessly connect to each other, for example, in an ad-hoc wireless network or via a 3GPP SL connection. Furthermore, any base station may be a station that provides wireless access, may be part of a radio access network (RAN), and / or may be a node connected to the RAN to control wireless access. For example, a base station may be an access point, for example, a Wi-Fi access point.

[0132] In this specification, whenever noise or signal-to-noise ratio (SNR) is mentioned, the corresponding steps, features or effects for noise and / or interference or signal-to-interference-and-noise ratio (SINR) are also disclosed.

[0133] 5 shows an example architecture of a satellite network with bent pipe transponders as one embodiment of an NTN 500. The illustrated elevation angle 516 of the service link is important because the elevation angle 516 affects the distance between a satellite as one embodiment of an NTN node 200′ and the wireless device 100, and the velocity of the satellite 200′ relative to the wireless device 100.

[0134] An NTN 500 (e.g., according to 3GPP) may include at least one of satellite communications and communications using high altitude platforms (HAPs) as examples of NTN nodes 200'. This section focuses on satellite communications, but the description provided is readily applied to at least one HAP 200' and a network of HAPs as the NTN 500.

[0135] The satellite radio access network as NTN500 consists of the following components: - at least one satellite as at least one NTN node 200', sometimes called a spaceborne platform; - an Earth-based gateway 518 connecting the satellites 200' to the base stations 200 and / or to the core network, for example depending on the architecture chosen; - a feeder link, i.e. a wireless link between the gateway 518 and the satellite 200'; an access link, i.e., a wireless link between the satellite 200′ and the wireless device 100; may comprise at least one of:

[0136] Depending on the orbital altitude (i.e., height), satellite 200′ may be categorized as a low Earth orbit (LEO), medium Earth orbit (MEO), or geostationary Earth orbit (GEO) satellite. LEO may include heights ranging from 250 km to 1,500 km, with orbital periods ranging from 90 minutes to 120 minutes, for example. MEO may include heights ranging from 5,000 km to 25,000 km, with orbital periods ranging from 3 hours to 15 hours. GEO may include heights at approximately 35,786 km and / or orbital periods of 24 hours.

[0137] A communications satellite typically generates several beams over a given area (i.e., coverage area). The beam footprint is usually elliptical in shape, which can be considered a TN cell 512. The beam footprint is sometimes called a beam spot (also called a spot beam). The beam footprint may move across the Earth's surface with the satellite moving, or it may be Earth-fixed with some beam-pointing mechanism used by the satellite to compensate for its motion. The size 524 of the beam spot depends on the system design and can range from tens of kilometers to thousands of kilometers.

[0138] FIG. 5 illustrates schematically an exemplary architecture of one embodiment of the NTN 500, comprising a satellite network, optionally together with bent pipe transponders.

[0139] The satellite orbits are determined based on ephemeris data. 3GPP has agreed that ephemeris data of a serving satellite 200′ should be provided to a wireless device 100 (e.g., a UE) to assist in, for example, pointing a directional antenna (or antenna beam) toward the satellite 200′. Alternatively or additionally, a wireless device 100 that knows its own location (e.g., based on a Global Navigation Satellite System (GNSS)) may use the ephemeris data to calculate and / or correct a timing advance (TA) and / or Doppler shift used when establishing a link to the satellite (e.g., when transmitting a random access preamble or performing a random access procedure).

[0140] In any aspect, an example includes a scenario in which wireless device 100 (e.g., UE) needs to be handed over to NTN 500 when wireless device 100 is leaving the coverage of TN 210 (i.e., the coverage area of ​​the TN and / or a TN cell of the TN), for example, as shown in FIG. 6A .

[0141] Before wireless device 100 (e.g., a UE) can establish and / or resume a connection to a target cell 512 in an NTN 500 (i.e., an NTN cell 512 of an NTN 500), wireless device 100 may need to determine the location of satellite 200' NTN coverage (i.e., satellite 200' embodying an NTN node) and / or the location of wireless device 100 itself. For example, the wireless device may determine timing advance (TA) pre-compensation prior to triggering a random access (RA) procedure to target cell 512 (e.g., to transmit an RA preamble) based on control message 520. Without control message 520, this would be a time-consuming task that degrades end-user performance experienced, for example, when wireless device 100 connects to NTN 500 for the first time after powering on wireless device 100.

[0142] In any aspect, another example includes a scenario in which a wireless device 100 (e.g., a UE) performs radio resource management (RRM) measurements 304 (briefly, NTN measurements) for (e.g., neighboring) NTNs, e.g., for at least one NTN cell 512 neighboring at least one TN cell 212 serving the wireless device 100. Such RRM measurements 304 are power consuming. For a wireless device 100 (e.g., a UE) experiencing coverage by both a TN 210 and an NTN 500, it may be wasteful to perform such NTN measurements when TN signal strength is adequate. Embodiments of the present technique may limit and / or control NTN measurements in accordance with control messages 520.

[0143] 6A and 7A schematically illustrate an embodiment of a wireless device (e.g., a UE) moving from the coverage of an embodiment of TN210 to the coverage of an embodiment of NTN500, and from the coverage of an embodiment of NTN500 to the coverage of an embodiment of TN210, respectively.

[0144] The TN 210 and the NTN 500 may be segments of a random access network (RAN) 600 .

[0145] In the detailed embodiments that follow, the wireless device 100 will be referred to as a UE for brevity and not limitation. Furthermore, any one of the detailed embodiments that follow may be implemented as such or in combination with any of the embodiments described above and / or any of the embodiments in the list of embodiments.

[0146] In a first detailed embodiment, a terrestrial network (TN) node 200 signals information (e.g., in a control message 520) regarding a non-terrestrial network (NTN) to a UE 100. The control message may support a handover of the UE 100 to the NTN 500. The information in the control message 520 includes assistance information, e.g., ephemeris, of a satellite 200′ that provides NTN coverage. Based on knowledge of the satellite ephemeris, the UE 100 may point its directional antenna or antenna beam toward the satellite 200′ to facilitate a handover from the TN 210 to the NTN 500.

[0147] In a first implementation of the first detailed embodiment, information (e.g., control message 520), e.g., ephemeris, may be provided via a system information (SI) broadcast in a source cell (e.g., TN cell 212) that is a neighbor (e.g., next door) cell to NTN cell 512 in NTN 500. This means, for example, that the information may be collected by all UEs in the TN cell, regardless of whether each UE has a possibility of being handed over to NTN cell 512 in NTN 500. In a variant, TN cell 212 may broadcast a reference point (e.g., NTN cell center 522) and / or distance (e.g., range or diameter 524 or some other representation), which instructs UE 100 when to start preparing to measure and / or access NTN 500, e.g., by determining and / or following satellite location (i.e., position) to determine a suitable time for (e.g., initial) transmission of a random access (RA) preamble (RAP).

[0148] In a second implementation of the first detailed embodiment, information (e.g., control message 520) may be provided as part of a handover command to UE 100 that should be handed over to NTN cell 512 in NTN 500. In this case, only UE 100 that should be handed over to NTN cell 512 in NTN 500 receives the information. Currently, SIB1 and SIB2 can be provided as part of the handover command, but if, for example, ephemeris information of a satellite that provides NTN coverage is specified to be provided in another SIB, that particular SIB is provided as part of the handover command. It is also possible that the information can be provided via an explicit set of field parameters rather than the above or some system information block (SIB).

[0149] In a third implementation of the first detailed embodiment, the TN 210 broadcasts only an indication that NTN-related information is available, for example, in an SIB (e.g., as a first instance of the control message 520). The UE 100 may then request that the information be sent in a second instance of the control message 520, for example, via dedicated signaling (e.g., RRC signaling). The context here may be that the UE 100, even if technically NTN-capable, may still not want to be handed over to the NTN, for example, because handover may involve additional costs for the user of the UE 100. In this way, the TN 210 may be able to know which UEs 100 should be handed over to the NTN and which UEs 100 should not be handed over to the NTN.

[0150] In a fourth implementation of the first detailed embodiment, when NTN-enabled UE 100 (i.e., one embodiment of UE 100) is powered on, UE 100 may first search for TN cell 212, signal information (e.g., control message 520) about NTN 500 and / or decode information (e.g., control message 520) transmitted from TN cell 512 about NTN 500, and / or then utilize assistance information (e.g., control message 520) to search for NTN cell. Alternatively, NTN-enabled UE 100 (i.e., one embodiment of UE 100) may first search for NTN cell 512 for a period of time. If the UE 100 is unable to find the NTN cell 512 after a period of time, the UE 100 may receive information (e.g., control message 520) transmitted from the TN cell 512 regarding the NTN 500 and / or may then utilize assistance information (e.g., control message 520) to search for the NTN cell 512.

[0151] In a fifth implementation of the first detailed embodiment, the UE 100 signals to the network that the UE 100 is capable of TN-NTN dual connectivity (DC). The UE 100 (e.g., in response to the signaling of TN-NTN DC capability) is configured (e.g., by the TN node 200) with a master cell group including one or more of the TN cells 212 (e.g., denoted as a TN MCG) and a secondary cell group including one or more NTN cells 512 (e.g., denoted as an NTN SCG). The TN 210 transmits system information (SI) (e.g., as an example of a control message 520) of the NTN SCG through signaling in the TN MCG.

[0152] 6B schematically shows a signaling diagram for handover of a UE 100 from a TN 210 to an NTN 500, for example, according to a first detailed embodiment. Step 302 may include sub-step 302-A of receiving a first instance of a control message 520 (e.g., from a TN node 200), which triggers or configures (e.g., conditionally triggers) the UE 100 to begin measuring 304 the RSS of at least one NTN cell 512. Optionally, the measured RSS is reported to the TN node 200. Depending on the measured RSS, for example, in response to a second instance of the control message 520 received in response to the measurement report, the UE initiates 306 an access procedure to establish or resume a connection with at least one NTN node 200′.

[0153] Steps 402-A, 404, and 402-B of method 400 correspond to steps 302-A, 304, and 302-B of method 300.

[0154] In a second detailed embodiment, which may be implemented alone or in combination with the first detailed embodiment, the NTN node 200′ signals information (e.g., control message 520′) regarding the TN 210 to the UE 100. Figure 7A schematically illustrates a RAN 600 that includes an embodiment of the TN 210 and the NTN 500, and an embodiment of a UE 100 to be handed over from the NTN 500 to the TN 210.

[0155] For example, in the signaling diagram of FIG. 7B, steps 402′-A, 404′, and 402′-B of method 400′ correspond to steps 302-A, 304, and 302-B of method 300.

[0156] The control message 520′ is for supporting a handover (HO) of the UE from the NTN 500 to the TN 210. This information, i.e., the control message 520′, includes assistance information, for example, the cell ID and / or carrier frequency of the TN cell 212 (e.g., as the target cell). Based on knowing the information about the TN 210 (e.g., the TN cell 212), the UE 100 may start measuring the TN 210 (e.g., the TN cell 212) to prepare for the handover from the NTN 500 to the TN 210.

[0157] In one embodiment of a UE 100 that supports NTN features, i.e., the UE 100, a conditional HO (CHO) command may be provided or may be provided (e.g., by the TN 210) in control command 520. The CHO command may be a handover command that is subject to a condition. The condition may include a location threshold for the location of the UE 100 (e.g., relative to the NTN cell 512 and / or the NTN node 200′), and / or an RSS TN threshold for the RSS of the TN 210, and / or an RSS NTN threshold for the RSS of the NTN, and / or, for example, a comparison between the RSS of the TN and the RSS of the NTN 500 to perform the HO.

[0158] In another detailed embodiment, or a variation of the second detailed embodiment, the TN node 200 may provide the UE 100 with an extended CHO command to the NTN 500, the extended CHO command having a second location threshold that guides the UE as to when the UE is close to the actual location threshold for performing HO and, therefore, when to start measuring 304 the NTN cell 512. This may be beneficial because the NTN cell 512 may have very wide RSRP level coverage, and the UE 100 may be able to successfully detect and measure the NTN cell 512 in advance when the UE 100 is actually assumed to HO to the NTN 500. From a system perspective (e.g., a second device aspect), the TN 210 may have better capabilities for serving the UE 100 (e.g., a higher data rate compared to the NTN 500), so the UE 100 may access the NTN 500 only when TN coverage is not adequate.

[0159] In another embodiment, or a variation of the first detailed embodiment, the terrestrial network (TN) node 200 signals information (e.g., an instance of control message 520) including an almanac for the GNSS or any navigation satellite system. The almanac may include coarse orbit and / or status information and / or associated ionospheric model and / or time relationship information for a navigation satellite (or satellite 200′) in the constellation of the GNSS or any navigation satellite system, e.g., so that handovers between the TN 210 and the NTN 500 can be performed with better service continuity.

[0160] The UE 100 may consider the information (e.g., control message 520) provided as an implicit instruction to turn on the GNSS receiver for GNSS and / or speed up the warm-up phase by, for example, reducing the time required to collect the orbit of at least one satellite 200′ and / or status information of the navigation satellites in the GNSS or any navigation satellite system or constellation of satellites 200′. Another benefit may include reduced power consumption of the UE 100.

[0161] In a first implementation (e.g., of the first and / or second detailed embodiments), such information (e.g., control message 520 or 520′) may be provided via a system information (SI) broadcast in a source cell that is a neighbor of NTN cell 512 (e.g., a target or serving cell) in NTN 500. This may mean that the information will be collected by all UEs 100 in TN cell 212 or NTN cell 512, regardless of whether they may be handed over to TN cell 212 in TN 210 or to NTN cell 512 in NTN 500.

[0162] In a second implementation (e.g., of the first and / or second detailed embodiments), the information (e.g., control information 520 or 520′) may be provided as part of a handover command to UEs 100 that are to be handed over to a cell in TN 210 or in NTN 500. In this case, only UEs 100 that are to be handed over to a cell in TN 210 or in NTN 510 receive the information.

[0163] In a third dependent embodiment, information may be provided to the UE via dedicated signaling that takes into account the possibility of an impending handover based on measurement reports provided by the UE 100 (e.g., in step 304), so that the UE 100 has sufficient time to turn on the receiver for the navigation system in advance before receiving the handover command.

[0164] Triggering to provide information to the UE can be based, for example, on the first time the UE 100 reports after a configured event is met, or the frequency of reporting, or a threshold for a particular measurement is reached. This can be up to the network implementation, or a request from the UE 100 can be provided to the TN 210.

[0165] 8 shows a schematic block diagram for one embodiment of device 100. Device 100 comprises processing circuitry, e.g., one or more processors 804, for performing method 300, and memory 806 coupled to processor 804. For example, memory 806 may be encoded with instructions that implement at least one of modules 102, 104, and 106.

[0166] The one or more processors 804 may be one or more combinations of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode, and / or encoded logic, either alone or in conjunction with other components of device 100, such as memory 806, operable to provide transmitter and / or wireless device functionality. For example, the one or more processors 804 may execute instructions stored in memory 806. Such functionality may include providing various features and steps described herein, including any of the benefits disclosed herein. The phrase "a device operable to perform an action" may indicate that device 100 is configured to perform an action.

[0167] 8, device 100 may be embodied by a wireless device 800, e.g., functioning as a transmitter and / or a UE. Wireless device 800 comprises a wireless interface 802 coupled to device 100 for wireless communication with one or more network nodes (i.e., base stations), e.g., functioning as TN node 200 and / or NTN node 200′.

[0168] 9-1 shows a schematic block diagram for one embodiment of device 200. Device 200 comprises processing circuitry, e.g., one or more processors 904, for performing method 400, and memory 906 coupled to processor 904. For example, memory 906 may be encoded with instructions that implement module 202.

[0169] The one or more processors 904 may be one or more combinations of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode, and / or encoded logic, either alone or in conjunction with other components of device 200, such as memory 906, operable to provide receiver and / or network node functionality. For example, the one or more processors 904 may execute instructions stored in memory 906. Such functionality may include providing various features and steps described herein, including any of the benefits disclosed herein. The phrase "a device operable to perform an action" may indicate that device 200 is configured to perform an action.

[0170] As shown schematically in Figure 9-1, device 200 may be embodied by a terrestrial network (TN) node 900, e.g., functioning as a receiving base station and / or gNB. TN node 900 comprises a radio interface 902 coupled to device 200 for wireless communication with one or more wireless devices, e.g., functioning as UEs.

[0171] 9-2 shows a schematic block diagram for one embodiment of device 200'. Device 200' comprises processing circuitry, e.g., one or more processors 904', for performing method 400', and memory 906' coupled to processor 904'. For example, memory 906' may be encoded with instructions that implement module 202'.

[0172] The one or more processors 904′ may be one or more combinations of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode, and / or encoded logic, either alone or in conjunction with other components of device 200′, such as memory 906′, operable to provide receiver and / or network node functionality. For example, the one or more processors 904′ may execute instructions stored in memory 906′. Such functionality may include providing various features and steps described herein, including any of the benefits disclosed herein. The phrase “device operable to perform an action” may indicate that device 200′ is configured to perform the action.

[0173] As shown schematically in FIG. 9-2, the device 200′ may be embodied by a non-terrestrial network (NTN) node 900′, functioning, for example, as a receiving base station and / or a satellite and / or a HAP. The NTN node 900′ comprises a wireless interface 902′ coupled to the device 200′ for wireless communication with one or more wireless devices, functioning, for example, as UEs.

[0174] 10 , according to one embodiment, a communication system 1000 includes a communication network 1010, such as a 3GPP-type cellular network, comprising an access network 1011, such as a wireless access network, and a core network 1014. The access network 1011 includes multiple base stations 1012 a, 1012 b, 1012 c, such as NBs, eNBs, gNBs, or other types of wireless access points, each defining a corresponding coverage area 1013 a, 1013 b, 1013 c. Each base station 1012 a, 1012 b, 1012 c can be connected to the core network 1014 via a wired or wireless connection 1015. A first user equipment (UE) 1091 located in the coverage area 1013 c is configured to wirelessly connect to or be paged by the corresponding base station 1012 c. A second UE 1092 in the coverage area 1013a can wirelessly connect to the corresponding base station 1012a. Although multiple UEs 1091, 1092 are shown in this example, the disclosed embodiments are equally applicable to situations where only one UE is in the coverage area or connects to the corresponding base station 1012a.

[0175] Any of the base station 1012 and the UEs 1091, 1092 may embody the device 100.

[0176] The communications network 1010 is itself connected to a host computer 1030, which may be embodied in hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 1030 may be owned or controlled by a service provider, or may be operated by or on behalf of the service provider. Connections 1021, 1022 between the communications network 1010 and the host computer 1030 may extend directly from the core network 1014 to the host computer 1030 or may proceed through an optional intermediate network 1020. The intermediate network 1020 may be one of a public network, a private network, or a hosted network, or a combination of two or more of them; the intermediate network 1020 may be a backbone network or the Internet, if present; and in particular, the intermediate network 1020 may comprise two or more subnetworks (not shown).

[0177] The communication system 1000 of FIG. 10 , as a whole, enables connectivity between one of the connected UEs 1091, 1092 and a host computer 1030. The connectivity may be described as an over-the-top (OTT) connection 1050. The host computer 1030 and the connected UEs 1091, 1092 are configured to communicate data and / or signaling via the OTT connection 1050 using the access network 1011, the core network 1014, any intermediate networks 1020, and possible further infrastructure (not shown) as intermediaries. The OTT connection 1050 may be transparent in the sense that the participating communication devices through which the OTT connection 1050 passes are unaware of the routing of the uplink and downlink communications. For example, the base station 1012 does not need to be informed about the past routing of an incoming downlink communication involving data originating from the host computer 1030 that is to be forwarded (e.g., handed over) to the connected UE 1091. Similarly, base station 1012 does not need to be aware of the future routing of outgoing uplink communications originating from UE 1091 and destined for host computer 1030 .

[0178] With method 300 performed by any one of UE 1091 or 1092 as wireless device 100, and / or method 400 performed by any one of base stations 1012a and 1012c as TN node 200, and / or method 400′ performed by base station 1012b as NTN node 200′, the performance or range of OTT connection 1050 may be improved, e.g., with respect to increased throughput and / or reduced latency. More specifically, host computer 1030 may instruct RAN 600 or TN 210 or NTN 500 or TN node 200 or NTN node 200′, or wireless device 100 (e.g., on the application layer) the QoS of traffic or any other explicit or implicit trigger to implement the present techniques.

[0179] An exemplary implementation of the UE, base station, and host computer described in the previous paragraph, according to one embodiment, will now be described with reference to FIG. 11 . In the communication system 1100, the host computer 1110 comprises hardware 1115, including a communication interface 1116 configured to set up and maintain wired or wireless connections with interfaces of different communication devices of the communication system 1100. The host computer 1110 further comprises processing circuitry 1118, which may have storage and / or processing capabilities. In particular, the processing circuitry 1118 may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown), adapted to execute instructions. The host computer 1110 further comprises software 1111, which is stored on or accessible by the host computer 1110 and executable by the processing circuitry 1118. The software 1111 includes a host application 1112. The host application 1112 may be operable to provide services to a remote user, such as a UE 1130 connecting via an OTT connection 1150 terminating at the UE 1130 and the host computer 1110. In providing services to the remote user, the host application 1112 may provide user data to be transmitted using the OTT connection 1150. The user data may depend on the location of the UE 1130. The user data may include auxiliary information or precision advertisements (also advertisements) delivered to the UE 1130. The location may be reported by the UE 1130 to the host computer, e.g., using the OTT connection 1150, and / or by the base station 1120, e.g., using the connection 1160.

[0180] The communications system 1100 further includes a base station 1120 provided therein, the base station 1120 comprising hardware 1125 that enables the base station 1120 to communicate with the host computer 1110 and the UE 1130. The hardware 1125 may include a communications interface 1126 for setting up and maintaining wired or wireless connections with interfaces of different communications devices of the communications system 1100, as well as a wireless interface 1127 for setting up and maintaining at least a wireless connection 1170 with a UE 1130 located in a coverage area (not shown in FIG. 11 ) served by the base station 1120. The communications interface 1126 may be configured to facilitate a connection 1160 to the host computer 1110. The connection 1160 may be direct, or alternatively, the connection 1160 may pass through a core network of the communications system (not shown in FIG. 11 ) and / or one or more intermediate networks external to the communications system. In the illustrated embodiment, the hardware 1125 of the base station 1120 further includes processing circuitry 1128, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The base station 1120 further has software 1121 stored internally or accessible via an external connection.

[0181] The communication system 1100 further includes the previously mentioned UE 1130. The hardware 1135 of the UE 1130 may include a wireless interface 1137 configured to set up and maintain a wireless connection 1170 with a base station serving a coverage area in which the UE 1130 is currently located. The hardware 1135 of the UE 1130 further includes a processing circuit 1138, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The UE 1130 further includes software 1131 stored on or accessible by the UE 1130 and executable by the processing circuit 1138. The software 1131 includes a client application 1132. The client application 1132, with the support of the host computer 1110, may be operable to provide services to a human or non-human user via the UE 1130. On the host computer 1110, a running host application 1112 may communicate with a running client application 1132 via an OTT connection 1150 that terminates at the UE 1130 and the host computer 1110. In providing services to a user, the client application 1132 may receive request data from the host application 1112 and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The client application 1132 may interact with the user to generate the user data that the client application 1132 provides.

[0182] It should be noted that the host computer 1110, base station 1120, and UE 1130 shown in Figure 11 may be equivalent to the host computer 1030, one of the base stations 1012a, 1012b, and 1012c, and one of the UEs 1091 and 1092, respectively, of Figure 10. That is, the inner workings of these entities may be as shown in Figure 11, and separately, the surrounding network topology may be that of Figure 10.

[0183] 11, the OTT connection 1150 is depicted abstractly to show communication between the host computer 1110 and the UE 1130 via the base station 1120, without explicit reference to intermediary devices and the exact routing of messages through these devices. The network infrastructure may determine the routing, and the network infrastructure may be configured to hide the routing from the UE 1130, the service provider operating the host computer 1110, or both. While the OTT connection 1150 is active, the network infrastructure may also make decisions to dynamically change the routing (e.g., based on load balancing considerations or reconfiguration of the network).

[0184] The wireless connection 1170 between the UE 1130 and the base station 1120 follows the teachings of embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT service provided to the UE 1130 using the OTT connection 1150, of which the wireless connection 1170 forms the final segment. More precisely, the teachings of these embodiments may reduce latency and improve data rates, thereby providing benefits such as better responsiveness and improved QoS.

[0185] Measurement procedures may be provided for the purpose of monitoring data rates, latency, QoS, and other factors that one or more embodiments improve upon. There may further be optional network functionality for reconfiguring the OTT connection 1150 between the host computer 1110 and the UE 1130 in response to fluctuations in the measurement results. The measurement procedures and / or the network functionality for reconfiguring the OTT connection 1150 may be implemented in software 1111 of the host computer 1110 or in software 1131 of the UE 1130, or both. In embodiments, sensors (not shown) may be deployed in or associated with communication devices through which the OTT connection 1150 passes, and the sensors may participate in the measurement procedures by providing values ​​of the monitored quantities exemplified above or other physical quantities from which the software 1111, 1131 may calculate or estimate the monitored quantities. The reconfiguration of the OTT connection 1150 may include message formats, retransmission settings, preferred routing, etc., and the reconfiguration need not affect the base station 1120, and the reconfiguration may be unknown or imperceptible to the base station 1120. Such procedures and functions may be known and practiced in the art. In some embodiments, the measurements may involve proprietary UE signaling that facilitates the host computer 1110's measurements of throughput, propagation time, latency, etc. The measurements may be implemented in software 1111, 1131 causing messages, particularly empty or "dummy" messages, to be sent using the OTT connection 1150 while the software 1111, 1131 monitors propagation time, errors, etc.

[0186] FIG. 12 is a flowchart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIGS. 10 and 11. For simplicity of this disclosure, only a drawing reference to FIG. 12 is included in this paragraph. In a first step 1210 of the method, the host computer provides user data. In an optional sub-step 1211 of the first step 1210, the host computer provides the user data by executing a host application. In a second step 1220, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 1230, the base station transmits the user data carried in the host computer initiated transmission to the UE, according to the teachings of the embodiments described throughout this disclosure. In an optional fourth step 1240, the UE executes a client application associated with the host application executed by the host computer.

[0187] FIG. 13 is a flowchart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIGS. 10 and 11. For simplicity of this disclosure, only a drawing reference to FIG. 13 is included in this paragraph. In a first step 1310 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides the user data by executing a host application. In a second step 1320, the host computer initiates a transmission carrying the user data to the UE. The transmission may be via a base station in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step 1330, the UE receives the user data carried in the transmission.

[0188] As is apparent from the above description, at least some embodiments of the present techniques more efficiently enable mobility (e.g., handover) from a TN to an NTN (e.g., from connectivity provided by a TN to connectivity provided by an NTN) and / or from an NTN to a TN (e.g., from connectivity provided by an NTN to connectivity provided by a TN). For example, latency and / or handover time and / or power consumption for handover may be reduced.

[0189] The many advantages of the present invention will be fully appreciated from the foregoing description, and it will be apparent that various changes may be made in the form, construction, and arrangement of units and devices without departing from the scope of the invention and / or without sacrificing all of its advantages. Because the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following claims.

Claims

1. A method (300) for supporting mobility (602; 602') of a wireless device (100; 800; 1091; 1092; 1130) between a terrestrial network (TN) (210) and a non-terrestrial network (NTN) (500), said method (300) being performed by said wireless device (100; 800; 1091; 1092; 1130), and comprising: receiving (302) a control message (520) from at least one TN node (200; 900; 1012a; 1012c; 1120) of the TN (210) at the wireless device (100; 800; 1091; 1092; 1130), the control message (520) indicating at least one NTN cell (512) of the NTN (500) for supporting the mobility (602) of the wireless device (100; 800; 1091; 1092; 1130) between the TN (210) and the NTN (500); Including, The method (300), wherein the control message further indicates a coverage area covered by at least one NTN node of the NTN (500) and at least one of a reference point of the coverage area, a center of the coverage area, and a size of the coverage area, which indicate the timing to start preparing the NTN for measurements and / or access.

2. the control message (520) indicates ephemeris data (514) of one or each of the at least one NTN node (200'; 900'; 1012b; 1120); The method (300) of claim 1, wherein the wireless device, based on the control message, directs a directional antenna of the wireless device toward the at least one NTN node or applies a precoder to multiple antennas of the wireless device to direct a wireless beam toward the at least one NTN node.

3. one of the at least one NTN cell is a target cell of the mobility; and The method (300) of claim 1, wherein at least one TN cell of the TN is a source cell of the mobility.

4. said at least one TN node (200; 900; 1012a; 1012c; 1120) of said TN (210) providing wireless access in at least one TN cell (212); At least one NTN node (200'; 900'; 1012b; 1120) of said NTN (500) provides wireless access in said at least one NTN cell (512); The control message (520) the location of the or each of said at least one NTN node (200'; 900'; 1012b; 1120); the speed of the or each of said at least one NTN node (200'; 900'; 1012b; 1120); and a trajectory (514) of the or each of said at least one NTN node (200'; 900'; 1012b; 1120); a cell identifier, cell ID, and / or carrier frequency of one or each of said at least one NTN node (200'; 900'; 1012b; 1120) or one or each of said at least one NTN cell (512); a handover command for handover of the wireless device (100; 800; 1091; 1092; 1130) from the at least one TN node (200; 900; 1012a; 1012c; 1120) or the at least one TN cell (212) to the at least one NTN node (200'; 900'; 1012b; 1120) or the at least one NTN cell (512); and the location of said wireless device (100; 800; 1091; 1092; 1130) relative to said at least one NTN node (200'; 900'; 1012b; 1120); an elevation angle (516) and / or an azimuth angle for uplink transmission from the wireless device (100; 800; 1091; 1092; 1130) to the at least one NTN node (200'; 900'; 1012b; 1120) and / or for downlink reception at the wireless device (100; 800; 1091; 1092; 1130) from the at least one NTN node (200'; 900'; 1012b; 1120); a timing advance (TA) for uplink transmission from said wireless device (100; 800; 1091; 1092; 1130) to said at least one NTN node (200'; 900'; 1012b; 1120) or pre-compensation of said TA; a precoder for beamformed transmission from said wireless device (100; 800; 1091; 1092; 1130) to said at least one NTN node (200'; 900'; 1012b; 1120); The method (300) of claim 1, further comprising:

5. At least one TN cell (212) of said TN (210) serves said wireless device (100; 800; 1091; 1092; 1130); and the at least one TN node (200; 900; 1012a; 1012c; 1120) is a serving node of the wireless device (100; 800; 1091; 1092; 1130); and The method (300) of claim 1, wherein the at least one TN cell (212) and the at least one NTN cell (512) are adjacent or overlapping cells.

6. measuring (304) a radio signal strength (RSS) of said at least one NTN node (200'; 900'; 1012b; 1120) or said at least one NTN cell (512) and reporting said measured RSS as requested by said control message (520); transmitting a random access preamble from said wireless device (100; 800; 1091; 1092; 1130) to said at least one NTN node (200'; 900'; 1012b; 1120) or said at least one NTN cell (512) according to said control message (520); performing a handover of the wireless device (100; 800; 1091; 1092; 1130) from the at least one TN node (200; 900; 1012a; 1012c; 1120) or the at least one TN cell (212) to the at least one NTN node (200'; 900'; 1012b; 1120) or the at least one NTN cell (512) according to the control message (520); The method (300) of claim 1, further comprising at least one of:

7. the wireless device (100; 800; 1091; 1092; 1130), leaving the coverage area of ​​said at least one TN cell; entering the coverage area of ​​the at least one NTN cell; and the RSS of said at least one NTN cell (512) is measured to be equal to or greater than a predefined RSS NTN threshold; 7. The method (300) of claim 6, wherein at least one of the steps of claim 6 is performed upon fulfillment of one of the following conditions:

8. 2. The method (300) of claim 1, wherein the control message (520) is broadcast in the system information (SI) of the at least one TN node (200; 900; 1012a; 1012c; 1120).

9. The SI indicates that the mobility of the wireless device (100; 800; 1091; 1092; 1130) between the TN (210) and the NTN (500) is supported; 2. The method (300) of claim 1, further comprising: sending a request to the at least one TN node (200; 900; 1012a; 1012c; 1120) based on the instruction in the SI, wherein the control message (520) is received (302) in response to the sent request.

10. searching NTN cells of said NTN (500) for a predefined period of time; If an NTN cell of said NTN (500) is not found within said predefined time period, sending a request to said at least one TN node (200; 900; 1012a; 1012c; 1120), said control message (520) being received (302) in response to said sent request; The method (300) of claim 1, further comprising:

11. A method (400) for supporting mobility (602) of wireless devices (100; 800; 1091; 1092; 1130) between a terrestrial network (TN) (210) and a non-terrestrial network (NTN) (500), said method (400) being performed by at least one node of said TN (210), transmitting (402) a control message (520) to the wireless device (100; 800; 1091; 1092; 1130), the control message (520) indicating at least one NTN cell (512) of the NTN (500) for supporting the mobility (602) of the wireless device (100; 800; 1091; 1092; 1130) between the TN (210) and the NTN (500); Including, The control message further indicates a coverage area covered by at least one NTN node of the NTN (500) and at least one of a reference point of the coverage area, a center of the coverage area, and a size of the coverage area, which support the wireless device in determining to start measurement and / or access preparation for the NTN, method (400).

12. A wireless device (100; 800; 1091; 1092; 1130) for supporting mobility (602; 602') of said wireless device (100; 800; 1091; 1092; 1130) between a terrestrial network (TN) (210) and a non-terrestrial network (NTN) (500), said wireless device (100; 800; 1091; 1092; 1130) being configured to perform any one of the steps described in any one of claims 1 to 10.

13. 12. A network node for supporting mobility of wireless devices between a terrestrial network (TN) and a non-terrestrial network (NTN), said network node being configured to perform the steps of claim 11.

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