Method and network infrastructure device

Abstract

A method by a communication device includes receiving a first signal from a non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network, the first signal being transmitted while the NTN infrastructure equipment is in a first track position, and determining a first measurement based on the received first signal. The method further includes receiving at least one further signal from the NTN infrastructure equipment at a time later than a time at which the first signal is received, the at least one further signal being received when the NTN infrastructure equipment is in one or more different track positions different from the first track position, and determining at least one further measurement based on the received at least one further signal. The method further comprises sending an indication to the wireless communication network over a wireless access interface provided by the wireless communication network for determining a relative difference between the determined first measurement and the determined at least one further measurement, a relative difference between the NTN infrastructure equipment and the communication device is determined for the wireless communication network to determine or verify a position of the communication device based on an indication of the determined first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at the first track position and one or more different track positions when the first signal and the at least one further signal are transmitted. The determined first measurement and at least one further measurement may be used to determine an observed time difference of arrival based on an interval of arrival time of a downlink signal transmitted by the NTN infrastructure equipment at a known time, the network or the NTN infrastructure equipment may determine or verify the location of the communication device through multipoint positioning by identifying the location of the NTN infrastructure equipment from the ephemeris information when transmitting the downlink signal. A corresponding example is disclosed in which a time difference of arrival of an uplink signal is used to determine or verify a location of a communication device.

Description

Technical Field

[0001] The present disclosure relates to a method for determining or verifying the location of a communication device or user equipment based on a signal transmitted or received by a non-terrestrial network (NTN) infrastructure device and an NTN infrastructure device and a communication device or user equipment. The present disclosure claims the Paris Convention priority of European Patent Application No. EP22174951.8, the entire contents of which are incorporated herein by reference in their entirety. Background Art

[0002] The "background technology" description provided herein is for the purpose of generally presenting the context of the present disclosure. The work of the presently named inventors, within the scope described in this background technology section and in aspects of the description that may not be prior art at the time of filing, is neither explicitly nor implicitly admitted to be prior art with respect to the present invention.

[0003] Wireless communication networks now support communication with a wider range of communication devices and user equipment for various applications and data traffic configurations and types. For example, the devices now supporting communication include reduced complexity devices, machine type communication (MTC) devices, high-resolution video displays, virtual reality headsets, etc. Some of these different types of devices may be deployed in very large numbers, such as low-complexity devices used to support the "Internet of Things", and may generally be associated with the transmission of relatively small amounts of data with relatively high latency tolerance. Other types of devices, such as supporting high-definition video streaming, may be associated with the transmission of relatively large amounts of data with relatively low latency tolerance.

[0004] In order to provide coverage for an increasing number of devices (such as IoT), 5G radio access technology (RAT) (also known as new radio (NR) system) includes aspects designed to support connectivity in various environments. For example, in order to improve the coverage of communication devices (user equipment, etc.), the wireless communication network may include infrastructure equipment installed on or forming part of a satellite, which is capable of providing coverage for wireless communication by sending and receiving radio signals to and from communication devices located on the earth. Such satellites can be geostationary satellites or located in low earth orbit or medium earth orbit, as will be explained in more detail below. Communication networks that include infrastructure equipment installed on or forming part of a satellite are called non-terrestrial networks (NTNs) and include 5G networks as well as future iterations and versions of existing systems. Such NTNs can be configured to provide a full range of services that would otherwise be provided by terrestrial wireless communication networks. However, some services, such as location-based services, may bring new challenges. Summary of the invention

[0005] The present disclosure may help solve or alleviate at least some of the problems discussed above.

[0006] An exemplary embodiment may provide a method of a communication device (user equipment UE), comprising: receiving a first signal from a non-terrestrial network (NTN) infrastructure device forming part of a wireless communication network, the first signal being sent when the NTN infrastructure device is in a first orbital position; determining a first measurement based on the received first signal; receiving at least one further signal from the NTN infrastructure device at a time later than the time of receiving the first signal, the at least one further signal being received when the NTN infrastructure device is in one or more different orbital positions different from the first orbital position; and determining at least one further measurement based on the received at least one further signal. The method also includes: sending an indication to the wireless communication network via a wireless access interface provided by the wireless communication network for determining a relative difference between the determined first measurement and the determined at least one further measurement, for the wireless communication network to determine or verify the position of the communication device based on the determined first measurement and the indication of the at least one further measurement, the relative difference being caused by the NTN infrastructure device being in the first orbital position and the one or more different orbital positions when the first signal and the at least one further signal were sent. The determined first measurement and at least one further measurement may be used to determine an observed time difference of arrival based on an inter-arrival time of a downlink signal sent by the NTN infrastructure equipment at a known time, such that the network or the NTN infrastructure equipment may determine or verify the position of the communication device by multilateration by identifying the position of the NTN infrastructure equipment from the ephemeris information when the downlink signal was sent.

[0007] An exemplary embodiment may provide a method performed by a communication device (user equipment UE), comprising: sending a first reference signal to a non-terrestrial network (NTN) infrastructure device forming part of the wireless communication network via a wireless access interface of the wireless communication network formed by NTN infrastructure devices, the first reference signal being sent at a time determined according to a reference forming part of the wireless access interface, and the first reference signal being sent when the NTN infrastructure device is in a first orbital position; sending at least one further reference signal to the NTN infrastructure device via the wireless access interface at a time later than the time of sending the first reference signal, the at least one further reference signal being sent when the NTN infrastructure device is in one or more different orbital positions different from the first orbital position, the at least one further reference signal being sent at a time determined according to the reference forming part of the wireless access interface. A time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface may be used to determine the position of the communication device by the wireless communication network, or to verify the position of the communication device based on measurements determined by the NTN infrastructure device. The time difference of arrival is caused by the NTN infrastructure device being in the first orbital position and the one or more different orbital positions when the first reference signal and the at least one further reference signal were sent.

[0008] Exemplary embodiments may provide a method for a communication device to make measurements based on downlink signals received from NTN infrastructure equipment, or for an NTN infrastructure to make measurements based on uplink signals received from a communication device, according to which the difference between the received signals may be used to determine or verify the location of the communication device.

[0009] Various aspects and features of the present disclosure are defined in the accompanying claims and include NTN infrastructure equipment and apparatus forming part of a wireless communication network for determining or verifying the location of a communication device / UE and methods thereof.

[0010] It should be understood that both the foregoing general description and the following detailed description are exemplary and not restrictive of the present technology.The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete understanding of the present disclosure and many of its attendant advantages will be readily appreciated as they become better appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference numerals refer to identical or corresponding parts throughout the several views, and in which:

[0012] Figure 1schematically represents some aspects of a 5G / new radio access technology (RAT) wireless telecommunications system that may be configured to operate in accordance with embodiments of the present disclosure;

[0013] Figure 2 is a schematic block diagram of exemplary infrastructure equipment and communication devices that may be configured to operate in accordance with embodiments of the present disclosure;

[0014] Figure 3 is an illustrative representation of a plurality of portions of infrastructure equipment forming a wireless communication network, wherein some portions of the infrastructure equipment are located in a satellite above the earth and other portions may be located on the ground of the earth, the portions forming part of an NTN wireless communication network;

[0015] Figure 4 is an illustrative representation of portions of an NTN wireless communications network serving user equipment, wherein some portions of infrastructure equipment are located in satellites above the earth and operate in a transparent manner;

[0016] Figure 5 is an illustrative representation of portions of an NTN wireless communications network serving user equipment, wherein some portions of infrastructure equipment are located in satellites above the earth and perform some base station functions;

[0017] Figure 6 is an illustrative representation of NTN infrastructure equipment in orbit above the Earth that forms a wireless communications network serving user equipment;

[0018] Figure 7 is an illustrative representation of triangulation performed on a user device in communication with three infrastructure devices (eNBs), showing a location-based determination method using a downlink time difference of arrival technique;

[0019] Figure 8 is an illustrative representation of a plurality of resource elements reserved for transmitting a reference signal in a wireless access interface according to certain aspects of the present disclosure;

[0020] Fig. 9 is a representation of a positioning opportunity transmission showing the location and length of the positioning opportunity transmission within a radio frame transmitted by the infrastructure equipment;

[0021] Fig.10 is a representation of an exemplary embodiment of the present disclosure showing a simplified representation of downlink transmissions of NTN infrastructure equipment carried by a satellite and user equipment for determining or verifying the location of a communication device / user equipment;

[0022] Fig.11is a representation of downlink communications and communication timing between NTN infrastructure equipment carried by a satellite and user equipment according to an exemplary embodiment of the present disclosure; Fig.12 is a representation of a connection procedure between a user device and a network according to an exemplary embodiment of the present disclosure;

[0023] Fig.13 is a representation of downlink and uplink communications and communication timing between NTN infrastructure equipment carried by a satellite and user equipment according to an exemplary embodiment of the present disclosure;

[0024] Fig.14 is a representation of an exemplary embodiment of the present disclosure, showing a simplified representation of communications between infrastructure equipment carried by a satellite and mobile user equipment according to an exemplary embodiment;

[0025] Fig.15 is a representation of an exemplary embodiment of the present disclosure, illustrating a message flow between a network, NTN infrastructure equipment, and a UE according to a downlink exemplary embodiment of the present disclosure; and

[0026] Fig.16A and Fig. 16B 1 represents an exemplary embodiment of the present disclosure, and illustrates a message flow between a network, an NTN infrastructure device, and a UE according to an uplink exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] New Radio Access Technology (5G)

[0028] Figure 1 An exemplary configuration of a wireless communication network using some terminology proposed for and used in NR and 5G is shown. Figure 1In the figure, a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 via connection interfaces represented by lines 16. Each of the TRPs 10 is arranged to send and receive signals via a wireless access interface within the radio frequency bandwidth available to the wireless communication network. Therefore, within the range for performing radio communications via the wireless access interface, each of the TRPs 10 forms a cell of the wireless communication network as represented by circle 12. Therefore, a wireless communication device 14 within the radio communication range provided by the cell 12 can send signals to and receive signals from the TRP 10 via the wireless access interface. Each of the distributed units 41, 42 is connected to a central unit (CU) 40 (which can be referred to as a control node) via an interface 46. The central unit 40 is then connected to a core network 20, which can contain all other functions required to send data for transmission to and from the wireless communication devices, and the core network 20 can be connected to other networks 30.

[0029] If familiar Figure 1 As will be appreciated by those experienced in the wireless communication network according to the 5G standard shown, the CU 40, DU 42 and TRP 10 refer collectively to functions traditionally performed by a network base station or, in 5G terminology, a gNB. As explained below, in an NTN network, one or more of the components forming the gNB may be installed or located on a satellite. In terms of the broad top-level functionality, the term network infrastructure equipment / access node may be used to encompass these elements and the more conventional base station type elements of a wireless telecommunications system. Depending on the application at hand, the responsibility for scheduling transmissions scheduled over the radio interface between the respective DU and the communication device may lie with the control node / central unit and / or the distributed unit / TRP.

[0030] The communication device 14 is Figure 1 1 is represented as being located within the coverage area of ​​the first communication cell 12. The communication device 14 can therefore exchange signaling with the first CU 40 in the first communication cell 12 via one of the distributed units / TRPs 10 associated with the first communication cell 12. The communication device 14 can be referred to as a mobile terminal, terminal or user equipment (UE), which includes a chipset and has functions corresponding to a UE device known for operating with a wireless communication network.

[0031] Figure 2 Provided Figure 1 A more detailed diagram of some of the components of the network shown in , with the hardware components indicated. Figure 2 As a simplified representation, Figure 1The TRP 10 shown in FIG. 1 includes a wireless transmitter 30, a wireless receiver 32, and a controller or control processor 34 that is operable to control the transmitter 30 and the wireless receiver 32 to send and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. Figure 2 As shown, the exemplary UE 14 is shown to include corresponding transmitter circuitry 49, receiver circuitry 48 and controller circuitry 44, the controller being configured to control the transmitter circuitry 49 and the receiver circuitry 48 to transmit signals representing uplink data to a wireless communication network via a wireless access interface formed by the TRP 10, and to receive downlink data as signals transmitted by the transmitter circuitry 30 and received by the receiver circuitry 48 in accordance with conventional operation.

[0032] The transmitter circuits 30, 49 and the receiver circuits 32, 48 (as well as other transmitters, receivers, and transceivers described with respect to the examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices to send and receive radio signals in accordance with, for example, the 5G / NR standard. The controller circuits 34, 44 (as well as other controllers described with respect to the examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset configured to execute instructions stored on a computer-readable medium such as a non-volatile memory. The processing steps described herein may be performed, for example, by a microprocessor in combination with a random access memory that operates in accordance with instructions stored on a computer-readable medium. For ease of presentation, in Figure 2 The transmitter, receiver and controller are schematically shown as separate elements in the figure. However, it will be understood that the functions of these elements can be provided in various different ways, such as using one or more appropriately programmed programmable computers, or one or more appropriately configured application specific integrated circuits / circuitry / chips / chip sets. It should be understood that the infrastructure equipment / TRP / base station and UE / communication device will typically include various other elements associated with their operating functions.

[0033] like Figure 2 As shown, the TRP 10 also includes a network interface 50 connected to the DU 42 via the physical interface 16. Thus, the network interface 50 provides a communication link for data and signaling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0034] The interface 46 between the DU 42 and the CU 40 is referred to as the F1 interface, which can be a physical interface or a logical interface. The F1 interface 46 between the CU and the DU can operate according to the specifications 3GPP TS 38.470 and 3GPP TS 38.473, and can be formed by optical fiber or other wired or wireless high-bandwidth connections. In one example, the connection 16 from the TRP 10 to the DU 42 is via optical fiber. The connection between the TRP 10 and the core network 20 can generally be referred to as a backhaul, which includes the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the F1 interface 46 from the DU 42 to the CU 40.

[0035] Non-Terrestrial Network (NTN)

[0036] An NTN aerial vehicle (such as a satellite or an aerial platform) can allow the connection of a communication device and a ground station, which may be referred to herein as an NTN gateway [1]. In the present disclosure, the terms NTN aerial vehicle and NTN vehicle are used to refer to a space vehicle, an aerial platform, a satellite, or any other entity that moves relative to a communication device and is configured to communicate with the communication device. Specifically, in some embodiments, the NTN aerial vehicle may be, for example, a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a high altitude platform system (HAPS), a balloon, or a drone.

[0037] Due to the wide coverage of services and the reduced vulnerability of space / airborne vehicles to physical attacks and natural disasters, non-terrestrial networks are expected to:

[0038] Facilitate the rollout of 5G services in unserved areas (isolated / remote areas, on aircraft or ships) and underserved areas (e.g. suburban / rural areas) that are not covered by terrestrial 5G networks, upgrading the performance of limited terrestrial networks in a cost-effective manner;

[0039] Enhance the reliability of 5G services by providing service continuity for passengers on M2M / IoT devices or mobile platforms (e.g. passenger vehicles, aircraft, ships, high-speed trains, buses) or ensuring service availability anywhere (especially for critical communications, future rail / maritime / aeronautical communications); and

[0040] Achieve scalability of 5G networks by providing efficient multicast / broadcast resources to deliver data to the network edge and even to user terminals.

[0041] These benefits are associated with either a separately operated non-terrestrial network (NTN) or an integrated terrestrial and non-terrestrial network. These benefits include at least improved coverage, user bandwidth, system capacity, service reliability or service availability, energy consumption, and connection density. It is expected that NTN components will play a role in at least the following verticals in 5G systems: transportation, public safety, media and entertainment, e-health, energy, agriculture, finance, and automotive. It should also be noted that the same NTN benefits apply to 4G and / or LTE technologies, and although NR is sometimes mentioned in this disclosure, the teachings and techniques presented herein are equally applicable to 4G and / or LTE.

[0042] Figure 3 An example of a communication device 306 communicating with the NTN 300 is schematically shown. Figure 3 The NTN 300 in the present invention is mainly based on an LTE-type or NR-type architecture. Many aspects of the operation of the NTN 300 are known and understood, and for the sake of brevity, they are not described in detail here. The operational aspects of the NTN not specifically described herein can be implemented according to any known technology (e.g., according to the current LTE standard or the proposed NR standard).

[0043] NTN 300 includes a core network portion 302 (which may be a 4G core network or a 5G core network) in communication connection with a radio network portion 301. Radio network portion 301 includes a base station 332 connected to a ground station (or NTN gateway) 330, which may be formed as separate devices and connected as shown, or may also be formed as a single entity that performs the functions of both the base station 332 and the ground station 330. Radio network portion 301 may perform Figure 1 The functions of TRP 10, DU 41, 42 or CU 40, or can more broadly perform the functions of a base station such as eNB or gNB according to the 4G or 5G standards.

[0044] The NTN 300 includes an NTN airborne vehicle 310 that includes communication circuitry 334 for communicating with a communication device 306 and a wireless network portion 301 via wireless communication links 314 , 312 .

[0045] The communication device 306 is located within a coverage area (or cell) 308 provided by the NTN 300. Figure 3 In the example shown, coverage area 308 is provided by a spot beam generated by communication circuitry 334 of NTN aerial vehicle 310. The boundaries of cell 308 may depend on the altitude of NTN aerial vehicle 310 and the configuration of one or more antennas of communication circuitry 334 through which communication circuitry 334 sends and receives signals from communication device 306.

[0046] The spot beam may be a "fixed earth beam" that covers a geographic area on the surface of the earth for a predefined period of time. Alternatively, the spot beam may be a "moving earth beam" that covers a constantly changing geographic area on the surface of the earth. In the example, the communication device 306 may determine based on certain decision criteria to switch from being served by an NTN aerial vehicle 310 that implements a "fixed earth beam" to an NTN aerial vehicle 310 that implements an "moving earth beam", or may determine based on similar criteria to switch from being served by an NTN aerial vehicle 310 that implements a "fixed earth beam" to an "moving earth beam" provided by the same NTN aerial vehicle 310. It is apparent that the communication device 306 is capable of determining these changes in both directions, that is, it is capable of determining to switch from a fixed beam to a mobile beam, and vice versa, and to switch between NTN aerial vehicles 310 that connect the communication device 306 to the NTN 300.

[0047] exist Figure 3 , ground station 330 is connected to communication circuit system 334 via wireless communication link 312. Communication circuit system 334 receives signals representing downlink data sent by radio network portion 301 on wireless communication link 312, and sends signals representing downlink data via wireless communication link 314 that provides a wireless access interface for communication device 306. Similarly, communication circuit system 334 receives signals representing uplink data sent by communication device 306 via wireless communication link 314, and sends signals representing uplink data to ground station 330 on wireless communication link 312. Wireless communication links 312, 314 may operate at the same frequency, or may operate at different frequencies.

[0048] The extent to which communications circuitry 334 processes received signals depends on the processing capabilities of communications circuitry 334, as described below with reference to Figure 4 and Figure 5 Explained in more detail.

[0049] Figure 4 An example of an NTN architecture based on an NTN aerial vehicle 310 operating in a transparent manner is shown, meaning that a signal received from a communication device 306 at the NTN aerial vehicle 310 is forwarded (to the communication device 306, to a ground station 330 on Earth, or to another NTN aerial vehicle) only through frequency conversion and / or amplification. In such an implementation, a wireless access interface (such as an NR Uu interface) connecting the communication device 306 and a base station 332 located on Earth is provided by the base station 332. In such an implementation, the base station 332 can be considered as an "NTN infrastructure device".

[0050] Figure 5An example of an NTN architecture is shown, in which the communication circuit system 334 of the NTN aerial vehicle 310 implements at least some base station functions. In this case, the communication circuit system 334 is an example of an "NTN infrastructure device". The communication circuit system 334 generates a wireless access interface (such as an NR Uu interface) connecting the NTN aerial vehicle 310 and the communication device 306. For example, the communication circuit system 334 can decode received signals and encode and generate transmitted signals. In other words, the communication circuit system 334 may include some or all functions of a base station (such as a gNodeB or eNodeB). In some examples, delay-sensitive functions (such as confirming the receipt of uplink data or responding to RACH requests) may be performed by the communication circuit system 334 that partially implements some functions of the base station. The wireless communication feeder link between the NTN aerial vehicle 310 and the ground station 330 can provide a connection between the communication circuit system 334 and the core network portion 302. In the scenario where the NTN aerial vehicle 310 implements at least some base station functions, the base station 332 located on the earth may not exist in the NTN 300.

[0051] As will be appreciated, the mobility of the coverage area 308 in the NTN may present technical challenges that may not occur in traditional terrestrial networks. For example, where the NTN airborne vehicle 310 is a LEO satellite, the NTN airborne vehicle 310 may complete an orbit of the Earth in approximately 90 minutes. In this case, the coverage area 308 generated by the NTN airborne vehicle 310 moves very quickly relative to a fixed observation point on the Earth's surface (e.g., a LEO may move at a speed of 7.56 km / s).

[0052] Deploy network elements as non-terrestrial networks (NTN)

[0053] An exemplary deployment of a 5G wireless communication network that can be used to improve coverage in some cases is the NR Non-Terrestrial Network (NTN), where multiple satellites in orbit are used for LEO / MEO deployments with a transparent mode of operation. In transparent mode, the satellite acts as a "bent pipe" carrying the RF signal, while the rest of the gNB functionality resides in ground infrastructure equipment on Earth, connected via ground stations or NTN gateways. However, there is a growing interest in regenerative satellites, where the gNB or part of the gNB functionality resides in the satellite. Thus, the satellite can carry the full gNB functionality, or each satellite can carry different gNB functionality, such as a CU, DU, or TRP / Remote Radio Head (RRH). Figure 6 An example is shown in .

[0054] exist Figure 66, multiple satellites 602, 624, 626 are shown in orbit around the earth 600, where each satellite includes some of the functionality of a gNB. For example, a first satellite 602 includes the functionality of a gNB and is connected to a core network 604 on the ground via an earth-to-satellite link 606. The first satellite 602 is represented by 602a, 602b, and 602c at different points in its flight, and is collectively referred to as the first satellite 602. The flight path 608 represents the flight path of the first satellite 602, and the representations 602a, 602b, and 602c are respective instances of the satellite at different points along the flight path. Another example is shown, where a CU 620 is located on the surface of the earth 600 and is connected to a gNB DU carried by a satellite 624 via an earth-to-satellite link 622. The satellite 624 carrying the gNB DU is connected to a satellite 626 carrying a TRP via a communication link 628.

[0055] As will be understood from the following description, the exemplary embodiments may be applied to both examples of an NTN-based gNB formed by a combination of a TRP 626 and a gNB DU 624 or an NTN carrier carrying a complete gNB 602.

[0056] The gNB 602 may transmit a beam 651 from a communication circuit system (not shown) that covers and provides a wireless access interface for a communication device such as a UE 14 in a cell 308 on the surface of the earth 600. It will be appreciated that this example corresponds to the earth-fixed beam example described above, as the cell 308 is depicted at the same location on the surface of the earth 600 at successive instances of the flight path of the satellite having the gNB functionality 602. This is not intended to limit the present disclosure to earth-fixed beams only, but includes earth-mobile beams as described above, mutatis mutandis to the implementation of the appended details as those skilled in the art will be able to apply them.

[0057] Need to verify UE location

[0058] As described above, exemplary embodiments may provide improvements in determining or verifying the location of a communication device (UE) in order to provide location-based services to the UE. Location-based services may be, for example, the location of the UE determined by the network so that the network provides services specific to the location of the UE, such as directing emergency services when the UE crosses a border but is still communicating with a neighboring network in another country. Similarly, applications running on the UE may provide certain services that either have determined the location of the UE or have been provided with the determined location of the UE. As will be appreciated, such location-based services depend on accurate determination of the location of the UE.

[0059] 3GPP TR 22.296

[14] has determined that in order to support regulated services and features (such as public warning systems, charging and billing, emergency calls, lawful interception, data retention policies for cross-border scenarios and international regions, and network access), the wireless network should be able to locate each UE in a reliable manner and determine the policies applicable to its operations based on its location. It is also recommended that network operators cannot trust the position determined and generated by the UE through its GNSS capability.

[0060] [3] also points out that the accuracy requirements of UE location vary depending on the application, for example:

[0061]

[0062] Table 1: UE location requirements for different location applications.

[0063] It should be noted that the accuracy used in the table above for lawful interception, public warning systems and charging and tariff notification is 2 km, which is equivalent to the accuracy achievable in terrestrial networks using cell ID positioning, and that these applications may have other requirements in addition to location accuracy, for example emergency call applications may require lower latency than other applications. A latency requirement may be that the establishment of an emergency call should not be delayed due to location requirements [3]. It should also be noted that in some cases the accuracy requirement for the emergency call procedure (i.e. 50m) may not be achieved, and similarly the latency requirement should ensure that the establishment of the emergency call is not delayed. More information can be found in references [2] to [8] which contain additional details on the network verification requirements for the UE location.

[0064] Therefore, one technical problem is to improve the determination or verification of the location of a UE being served by an NTN.As background, the following paragraphs provide an explanation of techniques for locating a communication device for use with a terrestrial wireless communication network, which may be helpful in understanding the description of the exemplary embodiments.

[0065] Observed Time Difference of Arrival (OTDOA)

[0066] One of the positioning techniques considered for IoT (i.e. eNB-IoT and fe-MTC) is Observed Time Difference of Arrival (OTDOA). This is a technique to determine the UE's location by measuring the time it takes for a signal to propagate between the UE and multiple gNBs / eNBs, which in turn can be used to triangulate the UE's location. This technique can be applied to uplink or downlink signals. Figure 7 This is shown graphically in FIG, which depicts three eNBs numbered 701, 702, and 703 and a UE 710.

[0067] The basic operation of calculating the time of arrival (TOA) from each eNodeB (i.e. from the downlink signal) can be described as follows:

[0068] 1. First, the UE receives a reference signal and then performs a cross-correlation with a locally generated reference signal.

[0069] 2. The cross-correlations from different subframes can be accumulated so that a good cross-correlation peak can be obtained.

[0070] 3. The measured time delay can be obtained from the estimated power delay profile (PDP), which can be reported as relative arrival time difference or absolute time.

[0071] 4. Repeat the above steps to obtain measured time delays from several eNodeBs (eg, reference eNodeB and neighboring eNodeBs).

[0072] 5. Reference Signal Time Difference (RSTD) measurements are obtained by subtracting the measured time delay of the neighboring eNodeB from the measured time delay of the reference (serving) eNodeB. The UE may send all RSTD measurements and RSTD measurement quality to a location server, or may process the RSTD measurements itself to determine its location.

[0073] exist Figure 7 In the example, UE 710 can measure the reference signal time difference (RSTD), which is the observed time difference between the target eNB and the reference eNB. In this example, UE 710 will measure the RSTD of two or more eNBs, such as eNB2 702 and eNB3 703 (i.e., three or more eNBs are involved because one of the eNBs is a reference eNB, eNB1 701 in this example), and can then process the RSTD measurements or send these RSTD measurements to a location server (not shown). After receiving the RSTD measurements, the location server can calculate the UE position based on these RSTD measurements using the known positions of the eNBs involved. That is, the location server performs triangulation (involving at least three eNBs) to determine the position of UE 710, such as Figure 7 The time difference report including the RSTD measurement to be sent to the location server may be a legacy reference signal time difference (RSTD) report specified for 3GPP LTE and NR systems.

[0074] The accuracy of the UE 710 location depends on the accuracy of the RSTD measurement. Figure 7 The arrival time from eNB1 has an accuracy of ΔT 1 , as shown by frequency band 704, represents the possible variation of the relative propagation difference measured with the base station (eNB1 701 in this example). Similarly, the arrival time of eNB2 has an accuracy ΔT as represented by the corresponding frequency band 705 2, and the arrival time of eNB3 has an accuracy ΔT similarly represented by frequency band 706 3 Obviously, the UE 710 is located at the intersection of these frequency bands, which is determined by the time difference and therefore the propagation distance from each of the base stations 701, 702, 703 transmitting to the UE 710. The accuracy of the time of arrival measurement depends on the quality of the measured reference signal and the bandwidth of the reference signal.

[0075] For greater accuracy, corresponding measurements may be made of the time differences of arrival of further signals from additional base stations not represented here. It will be appreciated that the signals transmitted by the base stations (eNB 701, 702, 703) may or may not be simultaneous; if not simultaneous, an offset in the base station transmission time, or the time of a separate transmission according to some shared timing system, may be provided to the UE to help it calculate the UE position.

[0076] The arrival time can be estimated using known signals, i.e. reference signals (RS), such as cell-specific reference signals CRS, primary synchronization signals PSS or secondary synchronization signals SSS. However, these RSs are subject to inter-cell interference and therefore positioning reference signals (PRS) were introduced in Rel-9. Figure 8 The RE (resource element) positions of a set of PRSs for an eNB within a physical resource block PRB are shown, the occupied position depends on the cell ID of the eNB. Up to six sets of PRS positions with different frequency shifts can be transmitted, so if one eNB per frequency shift is assumed, up to six different eNBs can be measured at one time. Note that eNBs sharing the same frequency shift will have different sequences to distinguish themselves.

[0077] Specifically, Figure 8 The possible PRS positions R in the time-frequency resource element grid are shown. 6 800, the grid represents OFDM symbols on the x-axis 801 and subcarriers on the y-axis 802, defining resource elements as individual carriers. OFDM symbols are grouped into time slots 804, 806 comprising seven OFDM symbols. Figure 8 As shown, two such grids are shown, one on the left for one or two PBCH antenna ports 810, and one on the right for four PBCH antenna ports 812. These two examples 810, 812 illustrate different configurations that can be implemented, and are intended (but not limited to) to represent the adopted configurations corresponding to different numbers of antenna ports.

[0078] also, Fig. 9 An additional indication of the location of reference signals within a frame broadcast by a base station is provided. A set of consecutive subframes 902 is reserved for transmitting reference signals, which are transmitted with a periodicity T PRS907 repeats.

[0079] PRS in N PRS = {1, 2, 4, 6} consecutive subframes, with a period of T PRS = {160, 320, 640, 1280} subframes. N of PRS transmissions PRS The consecutive subframes are called positioning opportunities. Positioning opportunities and period T PRS An example of Fig. 9 , where the positioning opportunity has a length N PRS =4 subframes, and occupies subframes 1, 2, 3 and 4.

[0080] Uplink Time Difference of Arrival

[0081] For the sake of completeness, additional information will now be given about the process by which a UE determines its position by an uplink time difference of arrival method, which, as described later, may be adapted to be implemented in accordance with several embodiments of the present disclosure. 3GPP NR also supports UTDOA (uplink time difference of arrival) and other positioning methods.

[0082] In uplink time difference of arrival (UTDOA), a communication device sends an uplink signal, such as a sounding reference signal (SRS), which is received by multiple infrastructure devices. The SRS (uplink pilot) sent from the communication device may arrive at these infrastructure devices at different times. The infrastructure devices (which may be synchronized with each other, for example, using time derived from a GPS receiver) determine these arrival times and may send these arrival times to a location server. The location server calculates the location of the communication device based on multilateration.

[0083] It is well known in the art that a UE can determine its position by using a global navigation satellite system (GNSS) such as GPS, GLONASS or other suitable systems. These systems determine the position of a receiving device such as a UE in a simplified manner based on triangulation of the device relative to multiple satellites (usually four satellites are required). However, there is a requirement that the network should have some way to determine or verify the position of the UE independently of the UE reporting its position. In some applications, providing technology for the network to verify the position of the UE is a regulatory requirement. If there are errors in the UE's position calculation, the difference between the UE's calculated position and its actual position may increase over time, resulting in significant errors and causing significant problems.

[0084] Potential NTN localization methods

[0085] Recent discussions [7] have identified various candidate NTN positioning methods for determining the location of a UE in an NTN network. These methods include:

[0086] RAT-related positioning technology based on similar terrestrial network technology

[0087] oDownlink Time Difference of Arrival DL TDOA, also known as Observed TDOA, OTDOA

[0088] oUplink Time Difference of Arrival UL TDOA or UTDOA for short

[0089] oRound Trip Time (RTT)

[0090] o Angle-based positioning methods (angle of arrival AoA, angle of departure AoD). It was observed that such positioning methods are not well suited for NTN due to the wide spot beams of its non-terrestrial elements.

[0091] RAT-independent positioning method based on terrestrial network technology

[0092] oGlobal Navigation Satellite System (GNSS)

[0093] oAssisted GNSS (A-GNSS)

[0094] oTerrestrial Beacon System (TBS)

[0095] In [4], it was observed that several terrestrial positioning techniques can be used to support verification of UE position using single or multiple satellites. There are many other techniques for determining the position of the UE in terrestrial networks, such as sensors, WLAN, Bluetooth, and Enhanced Cell ID (E-CID). The first three techniques depend on external systems / sensors and network assistance, and E-CID is a legacy E-UTRA positioning method. Several of them are being adapted for use in future NR standards.

[0096] The current 3GPP specifications define a method for identifying a UE or a communication device such as Figure 1 and Figure 2 The communication device 14 or Figure 3 The invention relates to a function of determining the absolute location of a UE 306 configured to operate in accordance with these specifications and to communicate with a wireless communication network operating in accordance with these specifications. The RTT uses a measurement of the round trip time of a signal between the communication device and a plurality of infrastructure devices to determine the distance between the communication device and each infrastructure device, from which a location corresponding to the communication device can be derived.

[0097] The above techniques, as well as OTDOA and UTDOA, rely on measurements (of signal strength and / or relative arrival time) of signals sent by the communication device 14 and received at infrastructure equipment of the wireless communication network, or measurements of signals sent by infrastructure equipment and received at the communication device 14.

[0098] Further details of the 3GPP positioning method are provided in

[11] .

[0099] The UE can determine its position via various RAT-independent means, such as GPS / GNSS as discussed above. These positioning methods are considered accurate. If the network itself can accurately locate the UE, then there is no point in the UE sending its own positioning report. The role of network verification of the UE position is not to compete with traditional positioning methods such as GPS, but to verify the UE position reported by the UE to the network.

[0100] Number of measurements required to verify UE position

[0101] GPS requires four measurements to determine the {latitude, longitude, altitude} of the communication device. Determining the GPS location requires the following steps:

[0102] UE receives reference signals from four or more satellites

[0103] UE calculates RSTD (reference signal time difference) or flight time for each satellite

[0104] Knowing the position of each satellite (via ephemeris information) and the synchronization status of the satellites (e.g., are the satellites synchronized), the UE can perform multilateration to determine its position. In some cases, if the satellites are not synchronized, the UE can offset the RSTD of some or all satellites based on the known timing differences between the satellites.

[0105] In contrast, for UE location verification, it may not be necessary to determine the UE's altitude. In this case, {latitude, longitude} can be determined from three measurements. Therefore, UE location verification requires fewer measurements than location determination, and in fact may not need to be determined to the same level of accuracy as the initial UE location determination.

[0106] In NTN systems, at any time, the UE may only be able to see a single (or a limited number of) satellites. This makes it difficult to perform traditional OTDOA or UTDOA positioning methods for UE location verification. Therefore, there is a need for a RAT-dependent UE location verification method that can operate with a single satellite.

[0107] The UE location verification method should be operable for various UE speeds (eg up to 500kmph).

[0108] Therefore, embodiments of the present disclosure provide a method and apparatus for accurately determining the position of a UE based on the measurement of the distance between the UE and a single satellite.

[0109] An exemplary embodiment may provide a method of a UE, comprising: receiving a first signal from an NTN infrastructure device forming part of a wireless communication network, the first signal being sent when the NTN infrastructure device is in a first orbital position; determining a first measurement based on the received first signal; receiving at least one additional signal from the NTN infrastructure device at a time later than the time of receiving the first signal, the at least one additional signal being received when the NTN infrastructure device is in an orbital position different from the first orbital position; and determining at least one additional measurement based on the received at least one additional signal. The method also includes: sending an indication to the wireless communication network, via a wireless access interface provided by the wireless communication network, for determining a relative difference between the determined first measurement and the determined at least one additional measurement, for the wireless communication network to verify a reported position of the communication device based on the determined first measurement and the indication of the at least one additional measurement, the relative difference being caused by the NTN infrastructure device being in the first orbital position and one or more different orbital positions when the first signal and the at least one additional signal were sent. As explained below, in one example, the NTN infrastructure device mounted on a satellite may periodically send a signal detected by the UE. However, in another exemplary embodiment, the signal is not sent periodically, but rather is sent at a time when the UE is notified so that the UE can receive the signal. By comparing the reception time of the signal, the relative difference in the position of the NTN infrastructure device when the signal is sent can be used to determine the distance difference between the UE and the NTN infrastructure device when the signal is sent. Since the wireless communication network will know the location of the NTN infrastructure device, when the signal is sent, the location of the UE can be determined or verified based on the time difference of the signal arriving at the UE. As will be understood, depending on the speed of the NTN infrastructure device and the time between the transmission of the first signal and at least one other signal, the difference in the orbital position of the NTN infrastructure device may be significant, thereby improving the accuracy with which the UE position can be estimated. Further exemplary embodiments will now be explained.

[0110] Measure the DL reference signal from the satellite at different times

[0111] Low Earth Orbit (LEO) satellites travel quickly across the sky. For example, when in orbit at an altitude of 600 km, a LEO satellite moves at a speed of 7.56 km / second. Therefore, if a reference signal referenced to the same satellite is measured at different times, the reference signal measurements will be made for the same satellite at different orbital positions (positions in the sky).

[0112] Fig.10 Shows Figure 61016 , for an exemplary configuration of a LEO satellite 602 and the distance between the satellite and the UE 14. In this example, the LEO satellite 602 is operating at an altitude of 600 km. As described above, a LEO satellite 602 in such an orbit travels at a speed of 7.56 km / second and therefore moves 151 km 1016 in 20 seconds. Therefore, as the satellite 602 moves from position A to position B, the distance between the satellite 602 and the UE 14 changes from 619 km 1017 to 600 km 1015 (by basic trigonometry). The UE 14 is considered to be located on the surface of the earth 1005, which is modeled as a flat plane, and any movement of the UE 14 is insignificant compared to the speed of the satellite 602.

[0113] As will be understood, Fig.10 is a simplified representation of the movement of the NTN vehicle, where the movement and distance shown are represented as linear, while in practice the NTN satellite 602 will move in an arc and the surface of the Earth will be as Figure 6 The arc is shown. However, without loss of accuracy, the principle used in this technique can be simplified to Fig.10 The linear representation of .

[0114] By approximating the speed of light to 3×10 8 m / s, the flight time of the signal from the satellite to the UE at different times corresponding to the transmission distances of 619km, 600km and 619km respectively can be calculated:

[0115] A (0 seconds): 2.063ms

[0116] B (20 seconds): 2.000ms

[0117] C (40 seconds): 2.063ms

[0118] Fig.11 A representation of the signal timing, the signal transmission time of satellite 602, and the corresponding time of arrival of the DL reference signal transmitted by satellite 602 at time 0 seconds, 20 seconds, and 40 seconds at UE 14 is shown, in a manner similar to the PRS for the terrestrial gNB described above. Fig.11 Due to the propagation time variation shown in , the arrival time of the DL reference signal received at UE 14 is delayed relative to the transmission time of satellite 602.

[0119] Examples A, B and C (in bold) correspond to Figure 6 and Fig.10 The positions of the satellites at positions A, B, and C. At position A, satellite 602 transmits a signal to UE 14, and the delay 1121 is 2.063 ms, as shown in FIG. Fig.11Satellite 602 waits 20 seconds 1122a before sending the second signal to UE 14, at which time satellite 602 has moved to position B. At this time, satellite 602 sends the second signal to UE 14, which has a lower propagation delay 1123 because satellite 602 has moved to a position closer to UE 14. Therefore, the time difference 1122b between the first signal and the second signal received by the UE is less than the time difference between the corresponding signals sent by satellite 602.

[0120] The opposite happens when satellite 602 travels from position B to position C, as the time of flight of the signal increases. Since positions C and A are equidistant from UE 14, the time of flight for C 1125 is the same as the time of flight for A 1121. Satellite 602, having passed position B, continues to position C and again waits 20 seconds 1124a before sending a third signal to UE 14. The increased distance between satellite 602 and UE 14 results in an increased time difference between the UE 14 receiving the signal sent by satellite 602 at B and at C, so that the time difference for this example is 20.000063 seconds.

[0121] Based on the reception time of these signals, in one example, the UE will report the following inter-arrival times of these transmission signals:

[0122] AB: 19.999937 seconds

[0123] BC: 20.000063 seconds

[0124] [Note that the exact signal form used may be different from the above. For example, the UE may signal the difference (delta) of the inter-arrival time from the transmission time interval of 20 seconds, i.e. the UE may report the time of {AB: -0.063ms, BC: +0.063ms}, which is the inter-arrival time difference].

[0125] The network can calculate the position of the UE 14 based on the known position of the satellite at different transmission times of the reference signal (i.e., at positions A, B, and C) and the arrival time difference of the reference signal, where the relevant TDOA in the example shown in the figure above is {AB: 0.063ms, BC: +0.063ms}. The above describes the UE position calculation method based on the arrival time difference and the known gNB position for the current specified DL-OTDOA technology for terrestrial networks. The arrival time difference of the reference two signals can be calculated as the difference between the arrival interval time of the two signals and the transmission time interval of the same two signals. The arrival interval time is the time difference as measured by the receiving body (i.e., the UE in the downlink example) between receiving two signals. The transmission time interval is the time difference as measured by the transmitting body (i.e., the satellite in the downlink example) between sending two signals.

[0126] Alternatively, the inter-arrival time between signal reception at the receiver and a reference time may be calculated, for example, a reference time on a clock at the UE that has been synchronized with a clock on a satellite or is known to be accurate (e.g., an atomic clock). In this example, only one signal is needed because the difference is taken between one received signal and the reference time.

[0127] A reference signal is a signal that can determine the time of arrival or other measurement. Examples of DL reference signals may include:

[0128] Positioning Reference Signal (PRS)

[0129] Channel State Information Reference Signal CSI-RS

[0130] Synchronization signal block SSB

[0131] Tracking reference signal TRS

[0132] or other such suitable signal.

[0133] Note that this positioning method can be used for more than one satellite as long as the network knows the timing of the DL signal from the satellite and the position of the satellite.

[0134] Note that the accuracy of TDOA measurements, when the signal is transmitted between the UE and the satellite, depends on the accuracy of the UE's clock during the observation period.

[0135] TDOA Signaling

[0136] The UE 14 may send TDOA measurements via RRC or MAC signaling.

[0137] TDOA measurements can be signaled in the following ways (refer to Fig.11 ):

[0138] After each reference signal is received. In this case, the TDOA measurements will signal when the satellite is at position 'B' and 'C'.

[0139] After receiving a set of reference signals. In this case, a TDOA measurement will be signaled after time C, where two TDOA measurements will be signaled: {TDOA between A and B, TDOA between B and C}.

[0140] Configuration information of DL reference signals for network verification of UE location may be signaled in system information. The configuration information may include resource allocation information of time and / or frequency resources for sending DL reference signals.

[0141] In some implementations, the network may signal an indication that the location verification information must be included in the RRC Setup Request message. This signaling may be carried in system information.

[0142] Fig.12 An exemplary signaling procedure for UE 1210 position verification using DL reference signals is shown. In step 1, network 1201 sends a system information block (SIB) to UE 1210, which contains ephemeris information for satellites with which UE 1210 can exchange signals. In this exemplary embodiment, UE 1210 can only exchange signals with one satellite, but the present disclosure is not limited to such a scenario. If UE 1210 can exchange signals with more than one satellite, network 1201 can send ephemeris information related to more than one satellite at this stage. The current 3GPP standard allows the network to send satellite ephemeris information related to 4 satellites to the UE.

[0143] In step 2, the network 1201 sends an additional system information block to the UE 1210, which contains the configuration of resource elements for transmission and reception of downlink reference signals. Thus, the UE 1210 knows the reference signals to be transmitted to it and their time and frequency allocation. In step 3, an additional SIB is sent by the network 1201 to the UE 1210, which includes an indication that the UE 1210 location verification should be included in any RRC setup request message.

[0144] In step 4, the UE determines the network required location verification information included in any RRC setup request based on the downlink reference signal.

[0145] In step 5, UE 1210 then attempts to set up an RRC connection with network 1201. In addition to the standard contents of an RRC setup request, this may involve UE 1210 sending to network 1201 its position as determined by GNSS, position verification information determined in step 4, data that may allow network 1201 to verify the position of UE 1210 (such as TDOA measurements), or other verification information as requested by network 1201, etc.

[0146] After this, the network 1201 may check the UE location report (e.g., determined using GPS or another GNSS) against the verification information provided to it in step 6. If the result of this check is satisfactory, the main data transfer between the UE 1210 and the network 1201 may begin, as seen in step 7.

[0147] It should be understood that some of these steps may be omitted from the above process, or may be performed in a different order than the above process, or indeed other steps may be included in the process. For example, the system information blocks may be sent in a different order than the above order, or there may be a step to convey to the UE 1210 that the location report check performed by the network in step 6 was successful.

[0148] Measuring UL reference signals from UE at different times

[0149] Example embodiments may also provide a method performed by a communication device (user equipment UE), comprising: sending a first reference signal to a non-terrestrial network (NTN) infrastructure device forming part of the wireless communication network via a wireless access interface of the wireless communication network formed by NTN infrastructure devices, the first reference signal being sent at a time determined according to a reference forming part of the wireless access interface (such as a frame boundary, a subframe boundary or other reference), and the first reference signal being sent when the NTN infrastructure device is in a first orbital position. The method comprises: sending at least one further reference signal to the NTN infrastructure device via the wireless access interface at a time later than the time of sending the first reference signal, the at least one further reference signal being sent at a time determined according to the reference forming part of the wireless access interface, the at least one further signal being sent when the NTN infrastructure device is in an orbital position different from the first orbital position. A time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface may be used by the wireless communication network to determine or verify the position of the communication device based on measurements determined by the NTN infrastructure device, the time difference of arrival being caused by the NTN infrastructure device being in different orbital positions when sending the first reference signal and the at least one further reference signal. Thus, knowing when the first reference signal and at least one further reference signal are transmitted, determining their time difference of arrival, or the time difference of the first reference signal and a reference forming part of the radio access interface, may determine or verify the position of the UE.

[0150] It is also possible to use UL TDOA techniques (or Round Trip Time, RTT, measurement techniques), where the UE sends some UL reference signals, such as Sounding Reference Signals SRS or UL channels, such as Physical Random Access Channels PRACH, and the network measures the arrival time of these UL reference signals at the satellite. The RTT technique is more resilient to clock drift issues at the UE, since the arrival time difference of the UL reference signals can be measured even when the UE's clock is synchronized with the DL frame timing.

[0151] Positioning / UE location verification using UL reference signals and RTT techniques Fig.13 Shown in. Fig.13 is based on Fig.10 The scene shown.

[0152] exist Fig.13 , instructing UE 1310 to send UL SRS at a known time relative to DL subframe timing. For simplicity, it can be considered that UE 1310 needs to send UL SRS to satellite 1301 immediately after the downlink subframe boundaries that occur at times 0 seconds, 20 seconds, and 40 seconds. UE 1310 knows when these DL subframe boundaries occur based on signaling of the system frame number (SFN), and UE 1310 is able to count subframes. The following transmissions and measurements occur:

[0153] · With respect to position A, the DL subframe timing at UE 1310 is 2.063 ms later than the DL subframe timing at satellite 1301 due to the flight time delay between the two 1321a. At the UE's DL subframe timing, UE 1310 transmits a UL SRS. Since the UE's DL subframe timing is 2.063 ms later than the DL subframe timing at satellite 1301, the transmission of the UL SRS is 2.063 ms later than the satellite's DL subframe timing. The UL SRS is affected by an additional propagation delay 1321b of 2.063 ms and therefore arrives at satellite 1301 4.126 ms after the satellite's DL subframe timing. Satellite 1301 can measure a 4.126 ms delay 1321 of UL SRS reception, which represents the round trip time from satellite 1301 to UE 1310. Therefore, the propagation delay between satellite 1301 and UE 1310 can be calculated as 4.126 / 2=2.063ms, which is equivalent to a distance of 619km. After this, satellite 1301 can send this data to the network, for example to the gNB or other base station controlling satellite 1301 and the transceiver functions of satellite 1301, and the network thus knows the position of UE 1310 619km from satellite 1301 at time 0 seconds. The network knows the position of satellite 1301 through signaling from the satellite ground station or through orbit calculations. Alternatively, the gNB can measure the delay between the DL subframe timing and the SRS reception and calculate the propagation time between the UE and the satellite, taking into account any delay on the feeder link between the gNB and the satellite.

[0154] For location B, a similar RTT calculation as that performed at "A" may be performed. At B, the satellite 1301 is closer to the UE 1310 (e.g., directly overhead), and the RTT is lower. At B, the RTT is measured to be 4.000 ms, plus the time that the UE's subframe timing lags behind the satellite's subframe timing and the flight time between the satellite 1301 and the UE 1310, equal to a distance of 600 km between the UE 1310 and the satellite 1301.

[0155] At C, a similar RTT calculation as that performed at "A" can be performed. At C, the distance between the satellite 1301 and the UE 1310 is the same as at "A". At C, the RTT is measured to be 4.126ms, which is equivalent to a distance of 619km between the UE 1310 and the satellite 1301. At "C", due to the orbital track of the satellite 1301, the satellite 1301 is in a significantly different position than when at "A", although the RTT is the same as the RTT measured at A.

[0156] Based on (1) the measured distances between UE 1310 and satellite 1301 at times "A", "B", and "C", and (2) the known positions of the satellites at times "A", "B", and "C", the network can triangulate the position of UE 1310.

[0157] Timing Advance of UL Signal

[0158] The UL signal used in this embodiment may be timing-advanced. The network may then determine the propagation time between the UE and the satellite as the sum of the propagation time derived from the timing advance applied to the UL signal and the difference between the received UL signal and the DL subframe timing. Many different configurations may be employed. For example, as part of current (Rel-17) NTN operation, the network may signal the UE a common timing advance to be applied. In rel-17, in addition to this common timing advance, the UE then applies an additional UE-specific timing advance. In the following embodiments, the UE may apply only the common timing advance, or may apply a UE-specific timing advance, or may apply both the common timing advance and the UE-specific timing advance.

[0159] The common timing advance applied for UE location verification may be the Rel-17 common timing advance, wherein no additional UE-specific timing advance is applied. That is, if the UE knows that UL signals will be used to verify location, the UE may only apply the common timing advance to these UL signals. For other UL signals, the UE may apply both the UE-specific timing advance and the common timing advance based on the signaling associated with these other UL signals. If the UE applies the correct UE-specific timing advance correction, this is more likely to result in the UL signal arriving at the receiver at the expected time, being received correctly, and at the same time not causing interference to other signals.

[0160] The signaling (e.g., RRC signaling) that notifies the UE of the UL signal to be used for location verification may be Rel-18 signaling. Rel-18 UEs are expected to be able to interpret this signaling, while earlier versions of UEs will not interpret the signaling. Therefore, legacy UEs will apply appropriate timing advances to legacy signals, and will not apply timing advances as described herein to Rel-18 location verification UL signals.

[0161] In some exemplary embodiments, the common timing advance is a value specifically used for UE location verification. In this embodiment, the network signals the UE a common timing advance value to be applied, which is specific to the purpose of UE location verification. For example, the common timing advance can be a timing advance that is accurate for a UE at the center of a satellite beam on Earth. Such a timing advance value will ensure that for any UE within the satellite beam, the maximum delay of the UL signal is the flight time corresponding to the propagation distance from the farthest edge of the beam to the satellite that is receiving the UL signal, because there is no additional bulk delay for the UL signal.

[0162] Alternatively, the UE may apply a timing advance signal signaled to it by the network. For example, when the network instructs the UE to send an UL signal, the network may also indicate the timing advance to be applied to the signal. For example, the network may determine a timing advance value that will be appropriate for the initially reported UE position (i.e., the position that needs to be verified). In this case, the network will expect the UL signal to arrive at a known time - if the UL signal is received at a different time, the initially reported UE position will not be verified.

[0163] In a separate embodiment, following transmission of an UL signal, the UE may indicate the UL timing advance that it applied to the UL signal. Following transmission of an UL signal for location verification, the UE signals an indication of the timing advance that it has applied to the UL signal. The network receiving the indication may then determine the complete propagation time based on the UL timing advance and the timing of the received UL signal.

[0164] Note that in Rel-17, the network may require the UE to send a timing advance report in order to inform the network of the timing advance applied. The timing advance report may be signaled periodically or triggered by an event, for example, the event being a timing advance change exceeding a threshold. Depending on the embodiment, an additional event may be that the UE has recently sent an UL signal for location verification.

[0165] In another embodiment, the UE may signal the applied UL timing advance, but it waits before sending other UL signals. The UE may send the message of the applied UL timing advance in a Physical Uplink Shared Channel PUSCH message. The network may measure the timing error in the received PUSCH and add it to the applied UL timing advance in order to determine the propagation time. This embodiment is based on the observation / insight that the PUSCH itself can be used to measure the timing of the signal received from the UE (no separate UL signal is required).

[0166] In an example, the message transmitted in the PUSCH may be a Rel-17 message indicating the UL timing advance, and it is either sent periodically or event triggered. In other words, the UE sends a PUSCH carrying a message indicating the UL timing advance, and the network measures its timing misalignment after receiving the message. The distance between the satellite and the UE is calculated based on the signaled UL timing advance and the measured timing misalignment.

[0167] Typically the network may perform some verification of the UE's position by measuring / monitoring the timing advance applied to signal transmissions (the network may be able to control this by sending a timing advance command to the UE, where the UE then performs the actual timing advance), where a timing aligned UL signal may indicate that the correct UE-specific timing advance has been applied and that the UE is therefore in the location it reported. In Rel-17, the UE determines its position based on GNSS and the positions of the satellites based on ephemeris information. Based on these position measurements, the UE applies a UE-specific timing advance. If the UE-specific timing advance is calculated correctly, transmissions from the UE should be timing aligned at the network (gNB) with transmissions from other UEs. If there is a consistent drift in the timing of the UL signals received from a particular UE, this will indicate that the UE is not in the location it reported (which may mean that the UE was unable to calculate its UE-specific timing advance correctly).

[0168] Therefore, in this embodiment:

[0169] When the received UL signals are consistently timed, the network verifies the UE location

[0170] • When the received timing of the UL signal drifts, the network may mark the UE location verification as failed.

[0171] In other exemplary embodiments of the present disclosure, the UL signal may not have a timing advance. In the case where the UL signal does not have a timing advance, the network ensures that any potential time period (window) during which the UL signal may be received is wide enough to accommodate the maximum possible variation in the reception time of the UL signal (taking into account the UE closest to the satellite receiving the UL signal and the UE farthest away). The window will also take into account the variation in the propagation time of any DL signal that schedules the UL signal (e.g., the physical downlink control channel PDCCH that schedules the UL signal), as the time at which these signals arrive at the UE will also depend on the propagation time.

[0172] In some embodiments, after receiving one or more signals from a UE by a non-terrestrial infrastructure device, a base station forming part of the non-terrestrial infrastructure device or to which the non-terrestrial infrastructure device has sent information contained in a signal and communicating with the UE may report information related to the UE to the wireless communication network, such as the location of the UE, the uplink arrival time corresponding to the signal sent by the UE and / or the transmission time of the downlink signal sent by the infrastructure device, the round trip time corresponding to the communication with the UE, or other information that may help the network to verify the location of the UE. It may do this using some dedicated communication resources over an air interface provided by the network, or another suitable medium for communication between the non-terrestrial infrastructure device and the wireless communication network. In addition, the non-terrestrial infrastructure device may send information related to the UE to the wireless communication network after receiving a single signal from the UE, or it may do so only after receiving a group of signals.

[0173] For uplink communications, as with downlink communications, a reference signal is defined as a signal whose arrival time can be determined. In the case of uplink, examples include:

[0174] Sounding Reference Signal SRS

[0175] Demodulation Reference Signal DMRS

[0176] Physical Random Access Channel PRACH

[0177] or other such suitable signal.

[0178] Measurement / UL signal periodicity

[0179] The periodicity of the measurements or UL signal transmissions depends on one or more of the following:

[0180] UE speed. When the UE is travelling at high speed, the measurement period may need to be shortened (ie, the time between measurements / UL signals may be shortened). This may be necessary because if the UE is moving fast, the reported UE position (the position that needs to be verified) will change faster.

[0181] The orbital velocity of the satellite. Note that while there is little difference in the orbital velocity of LEO satellites (the orbital velocity of a LEO-600 satellite is similar to that of a LEO-1200 satellite), medium earth orbit MEO (2000 to 36000 km altitude), and geostationary orbit GEO (approximately 36000 km altitude), satellites can have significantly lower orbital velocities. The orbital velocity of the satellite will affect the required periodicity of the measurement / UL signals (slower satellites will mean that the measurement / UL signals must be spaced further apart in time to achieve good multi-lateration). It should be noted that certain aspects of the present disclosure may not apply to GEO satellites, as those skilled in the art will be able to understand based on their technical knowledge.

[0182] · Orbital altitude of the satellite. LEO-1200 satellites have approximately the same velocity as LEO-600 satellites, but have an orbit altitude that is twice the altitude of the Earth's surface. Therefore, the angles used in any triangulation calculations for LEO-1200 satellites are smaller than those for LEO-600 satellites, and so the difference in UE satellite distances is reduced, which can result in a loss of accuracy in the position estimate obtained from the LEO-1200 satellite compared to the same procedure performed for the LEO-600 satellite. In order to have similar accuracy, it may be necessary to increase the triangulation angles for the LEO-1200 satellite by increasing the measurement period. In summary, for satellites in high orbits, the measurement period may need to be increased.

[0183] Verification of UE position without triangulation

[0184] The above embodiments have discussed triangulation / multilateration of the UE position based on measurements received from the UE or based on measurements of signals sent from the UE. However, the network does not need to triangulate the UE position to perform verification. As long as the network measures and verifies sufficient flight time / propagation time measurements between the satellite and the UE, the network can verify the UE position. For example, refer to Fig.10 and Fig.11 , if the network receives propagation time estimates of 2.063ms, 2.000ms, and 2.063ms, the network can verify whether the UE position reported to the network is correct.

[0185] In other words, the network may calculate the propagation times associated with the UE being at its reported position. If the network receives validation measurements consistent with these computed propagation times, the reported UE position may be considered validated.

[0186] Signaling of location and verification information for high-speed UEs

[0187] For high-speed UEs, it may not be possible to collate sufficient verification information before the UE has moved enough distance to render the verification information obsolete. In other words, there is no point in trying to verify the UE's position to an accuracy of 'x' meters if the UE can move more than 'x' meters during the time required to perform the verification.

[0188] To solve this problem, the UE can report the location estimate and verification information. For example:

[0189] UE can signal {latitude / longitude, DL-TDOA measurements}

[0190] UE may signal its updated latitude / longitude every time it sends a UL reference signal for verification purposes

[0191] Having a set of {location, verification} information consisting of multiple individual reports, the network can try to confirm that the set of information is consistent. Fig.14 An exemplary verification is shown in FIG. This location verification can be performed with Fig.10 The comparison is made with the location verification performed for a stationary UE in . Fig.14 A UE moving at a speed of 500 kmph is shown. This scenario shows the satellite at three points in time and positions A, B and C, where the UE is located at positions A', B' and C' respectively. Fig.10 The similarities between the two graphs will be highlighted.

[0192] A: Fig.14 The positions of the satellite and UE at A and A' are respectively Fig.10 The positions of UE 1410 and satellite 1401 at instance A are the same. Based on a satellite altitude of 600 km, the distance 1417 between satellite 1401 and UE 1410 is 619 km (A->A'). The propagation time for this distance is 2.063 ms.

[0193] B: Satellite 1401 at B and Fig.10 , has moved 151 km 1416 to position B, but UE 1410, moving at a speed of 500 kmph, has traveled 2.8 km 1426 to position B' in 20 seconds. Although UE 1410 has moved, due to the triangular nature of the situation, the distance 1415 from UE 1410 to satellite 1401 is still about 600 km. Therefore, Fig.10 As shown, the propagation time for this distance is 2.000ms.

[0194] ·C: Positions C and C' show Fig.10 and Fig.141426 from position B' to position C'. The distance 1417 from UE 1410 to satellite 1401 is now 617.3 km. The propagation time is 2.058 ms, compared to Fig.10 The 2.063ms in the video is shortened.

[0195] In this case, the UE will report its set of positions and validation measurements at points A', B' and C'. To validate the set of positions reported by the UE, the network will check for validation information consistent with propagation times of 2.063ms, 2.000ms and 2.058ms at satellite positions A, B and C respectively.

[0196] Fig.15 Describes an exemplary embodiment and is based on Fig.12 , and further provides a process for determining or verifying the UE location. Fig.15 An exemplary schematic representation of the message flow between the UE 1510, the non-terrestrial network infrastructure equipment NTN IE 1502 and the network 1501 is provided. Fig.15 In more detail Fig.12 The process steps are described to help illustrate the exemplary embodiments. Fig.12 Step 2 in is represented as Fig.15 Step 2 in , further represents the first stage 1520, wherein the system information block SIB carries the configuration format of the downlink reference signal to be received by the UE 1510. This corresponds to Fig.12 Step 2, such as Fig.15 As shown on the left, step number 1505 is indicated as "2". The two dashed lines 1521a and 1521b represent the communication of the configuration format of the DL reference signal from the NTN IE 1502 or the network 1501 (via the NTN IE 1502), indicating that when implementing this embodiment, one may decide to prefer one of the two presented options (communication from the NTN IE or the network). Specifically, the two exemplary options presented herein involve SIBs transmitted from the NTN IE 1521a or from another part of the network 1521b.

[0197] exist Fig.15 In the second stage 4 of the message flow, Fig.15 As shown in step number "4" on the left edge, UE 1510 receives downlink reference signals 1523, whose configuration format has been sent to UE 1510 in step 2. These reference signals include multiple signals, among which Fig.15, as an example, three reference signals from NTN IE to UE 1510 are represented by three arrows 1523a, 1523b and 1523c (collectively referred to as reference signals 1523). As will be appreciated by those skilled in the art, the present disclosure is not limited to three reference signals, and there may be more than three signals or less than three signals.

[0198] Still referring to the second stage 4 of the message flow, UE 1510 uses downlink reference signal 1523 to determine measurements 1524 related to downlink reference signal 1523. The process of determining the measurements is indicated by vertical line 1524a next to dashed line 1510a indicating UE 1510.

[0199] Referring now to the third stage 5, the UE 1510 may send the determined measurements related to the downlink reference signal 1523 to the NTN IE 1502, which may then forward the determined measurements to the network. These are represented by numerals 1525 and 1526, respectively, and by arrows 1525a and 1526a, and correspond to Fig.12 Step 5 of the exemplary process described in .

[0200] In the final stage 6, the network 1501, after receiving the determined measurements associated with the downlink reference signals 1523 received by the UE 1510, proceeds to use these measurements in combination with the ephemeris information associated with the NTN IE 1502, wherein for each of the reference signals 1523a, 1523b and 1523c, the ephemeris information associated with the NTN IE when these reference signals were transmitted is taken into account, as well as the transmission time of each downlink reference signal 1523 having the determined measurements associated therewith, to verify the position of the UE 1510. This is done by Fig.15 1528a and process step 1528. As explained above, using the ephemeris information valid when each downlink reference signal is sent and the time when the downlink reference signal 1523 is sent, the position of the UE can be verified by performing multilateration using the difference between the arrival interval time of the downlink reference signal 1523 and the position of the NTN IE when determining the measurement.

[0201] Fig.16A and Fig. 16B An exemplary embodiment of the present disclosure is depicted and a flow chart of an exemplary process for uplink determination or verification of UE location is presented. Fig.16A and Fig. 16B 16. The message flow between the UE 1610, the non-terrestrial infrastructure equipment NTN IE 1602 and the network 1601 (not shown) to which the NTN IE 1602 is connected is shown.

[0202] Similar stages of the uplink exemplary process are Fig.15 For example, Fig.16A The first stage on the left is numbered "2", indicating Fig.15 The corresponding stages in Fig.12 It should be understood that Fig.16A and Fig. 16B The process described in is for the uplink process used to determine or verify the UE location, while Fig.12 and Fig.15 is for the downlink process used to determine or verify the UE location. Fig.12 , Fig.15 , Fig.16A and Fig. 16B When the stages in the same process are indicated by the same number, this should be understood as the corresponding stage in the corresponding process, rather than the same stage in the corresponding process. Fig.16A The phase numbered "4" in the figure contains the reference signal transmission between the UE and the NTN IE, which corresponds to Fig.15 Reference signal transmission between UE and NTNIE in stage 4 of Fig.16A The signal in is an uplink signal sent by the UE, and Fig.15 The signal in is a downlink signal sent by NTN IE.

[0203] Fig.16A The process described in the first stage begins with Fig.16A The left side is numbered "2". In this stage, the system information block SIB carries the configuration format of the uplink reference signal 1620 received by the UE 1610. The SIB can be sent to the UE 1610 by the NTN IE 1602, or sent to the UE 1610 by the network 1601. This is depicted by the dashed arrows 1621a and 1621b from the NTN IE 1602 and from the network 1601, respectively, both of which terminate at the UE 1610.

[0204] exist Fig.16A In the second stage numbered "4" on the left, UE 1610 sends an uplink reference signal to NTN IE 1602, as shown at 1622. These uplink reference signals are labeled 1624a, 1624b, and 1624c, respectively, and may be collectively referred to as uplink reference signals 1624. As will be appreciated by those skilled in the art, in Fig.16A In some embodiments, there may be more than three uplink reference signals sent by UE 1610 to NTN IE 1602, or there may be less than three such uplink reference signals in other exemplary embodiments.

[0205] Still referring to the second stage, the time at which the UE 1610 sends the uplink reference signal 1624 may be determined by the SIB it receives in the first stage. For example, the UE 1610 may send the uplink reference signal 1624 to the NTN IE 1602 at a frame boundary, or at a subframe boundary, or at another time known to the NTN IE 1602 (e.g., three OFDM symbols after the frame boundary in the example where the frame contains OFDM symbols). Alternatively, the sending of the uplink reference signal 1624 from the UE 1610 may be in response to receiving a reference signal from the NTN IE 1602. These reference signals are sent at the NTN IE 1602. Fig.16A 1623a, 1623b and 1623c are represented by dashed arrows 1623a, 1623b and 1623c and are collectively referred to as reference signal 1623.

[0206] In the third stage of the process of determining or verifying the location of UE 1610, NTN IE 1602 may forward to the network an indication of the reception time of uplink reference signal 1624, such as Fig.16A 1626 in FIG. 1 and indicated by dashed arrow 1626a. Then, as Fig.16A 1628 and vertical line 1628a in the figure, the fourth stage of processing may be performed by network 1601. Network 1601 may use the ephemeris information associated with NTN IE 1602, wherein, for each of reference signals 1624a, 1624b, and 1624c, the ephemeris information associated with the NTN IE when these reference signals are received, as well as the reception time of each uplink reference signal 1624 and the transmission time of each reference signal 1623, to verify the position of UE 1610 based on multilateration.

[0207] In other exemplary embodiments, NTN IE 1602 may be able to process the reception time of the uplink reference signal and determine measurements based on the reception time of the uplink reference signal, such as the inter-arrival time of multiple uplink reference signals 1624, the round trip time of signals sent from NTN IE 1602 to UE 1610 and back to NTN IE 1602 from UE 1610, or other suitable measurements. In some exemplary embodiments, NTN IE 1602 may then send only these measurements to network 1601, rather than an indication of the reception time of uplink reference signals 1624. Network 1601 may then use these determined measurements to verify the location of UE 1610.

[0208] Fig. 16B from Fig.16AContinuing, another example of the final stage of processing the uplink reference signal to verify the location of the UE 1610 is provided. In some embodiments, the NTN IE 1602 may have sufficient processing power to perform processing of the reception time of the uplink reference signal 1624, as shown at 1630 and line 1630a. In this case, the NTN IE 1602 performs verification of the location of the UE 1610 and then sends an indication of the result of the UE location verification to the network 1601. For example, it may send an indication to the network 1601 that the UE 1610 has successfully verified its location, or it may send an indication to the network 1601 that the UE 1610 has failed the location verification process. This is depicted by reference numeral 1632 and shown by dashed arrow 1632a. If the location of the UE has been successfully verified, communication services may be provided to the UE, or previously requested communication services may be allowed to continue.

[0209] Other measurements for UE location verification

[0210] The embodiments described so far have focused on location verification using timing measurements. Those skilled in the art will appreciate that location verification may also be performed with reference to other measurements, and these measurements should not be considered beyond the scope of the present disclosure. For the avoidance of doubt, several additional embodiments are provided below, in which the present disclosure is implemented without utilizing timing measurements.

[0211] RSRP measurements can be used to provide an indication of the path loss between the UE and the satellite. Given a known transmit power, the known relationship between path loss and propagation distance can then be used to estimate the distance between the UE and the satellite. The UE position can then be multilaterated based on these distances. However, this implementation must take into account atmospheric effects and other factors that interfere with the transmission of signals over the air interface, such as cloud absorption.

[0212] The frequency offset of the signal from the UE depends on the position of the UE in the cell. For example, a UE directly below a satellite will have a low frequency offset due to the Doppler shift, while a UE with a low angle of incidence (i.e. the satellite is low on the horizon) will have a higher frequency offset. Therefore, the frequency offset / Doppler shift will provide some information about the UE's position that can be used to verify. For example, to verify whether a UE is located Fig.10 , the satellite / network can test high positive frequency offset, low frequency offset, and high negative frequency offset as the satellite moves from A to C.

[0213] Alternatively, while UE location verification involves verifying the location of the UE in the NTN system, the location may be verified by making measurements on the terrestrial system before reporting to the NTN system. This scenario is particularly applicable when the operator of the NTN system has a business / service relationship with the terrestrial network TN operator. This embodiment is also applicable to verifying the location of a Rel-17 UE, which will not implement any of the above-mentioned NTN RAT-related verification methods. The UE may make measurements on the terrestrial network and report these measurements to the NTN system. For example, the UE may make DL-TDOA measurements of the PRS from the terrestrial network and report them to the NTN system. The NTN system may then verify the location of the UE based on these measurements. This verification may help to understand the location of the TN gNB and / or communication with the location server (LCS).

[0214] Verify the security / reliability of information

[0215] The UE may provide incorrect verification measurements in order to deceive the system into believing that the UE is located at a location other than the UE actually is. Although the UE may attempt to spoof certain verification information, the present disclosure is still considered relevant for the purpose of UE location verification. While there is a certain degree of engineering work associated with sending an incorrect UE location, there is additional engineering work associated with spoofing verification information. Spoofing verification information requires a large amount of engineering work to modify the firmware within the device. For example, physical layer measurements and transmission timing may need to be changed. Protocol layers within the device may also need to be changed, and may be difficult to engineer in this manner and scope. In addition, the firmware within the device may be cryptographically signed, which makes it extremely difficult or impossible to modify the UE's firmware using spoofed verification codes.

[0216] Additional technical considerations

[0217] It will be understood that the present disclosure covers LEO, MEO, and in some cases GEO satellites, involving satellites at different altitudes, wherein the altitudes of two different satellites may differ by more than a factor of 10, e.g., a LEO satellite at 1200 km and a MEO satellite at 20,000 km altitude. Therefore, the propagation delay in the communication between a ground-based UE and a satellite may also vary by more than a factor of ten.

[0218] Therefore, some embodiments in which the NTN infrastructure equipment waits for a period of 20 seconds after sending a first signal (e.g., before sending a second signal) and waits an additional 20 seconds before sending a third signal may not be suitable for implementation in embodiments using satellites having orbital altitudes other than the exemplary orbital altitude of 600 km for the satellites in the above-described embodiments. Therefore, other thresholds and methods of determining when a transmission should be sent have been devised.

[0219] In some embodiments, knowing the altitude of the satellite to which the UE sends signals or from which the UE receives signals, the network can send an indication to the UE and / or the satellite of a threshold to be met for subsequent transmissions. In one exemplary embodiment, the network can determine that a 20 second delay between transmissions from the NTN satellite is sufficient. Alternatively, other time lengths can be determined and signaled to the UE and the satellite, such as 10 seconds, or 30 seconds, or a different time length.

[0220] In other exemplary embodiments, the threshold for determining when a transmission should be sent does not depend on time. In some exemplary embodiments, the network may calculate when the angle of incidence of the signal at the receiving entity (i.e., the UE in the downlink embodiment or the satellite in the uplink embodiment) has changed by a set amount. For example, the network may convey to the transmitter an indication of when to send the signal based on the time allowed for the angle of incidence of the signal when received at the receiving entity to change by 15 degrees, or some other angle predetermined by the network.

[0221] In other exemplary embodiments, the threshold for determining when a transmission should be sent does not depend on the time or the angle of incidence of the transmission at the receiving body. For example, the threshold may be that the satellite has traveled a certain distance. In this exemplary embodiment, the threshold may be that the transmitter may send a signal when the satellite has traveled a distance of 200 km from its previous position, or other suitable distance as predetermined by the network.

[0222] In other exemplary embodiments, the transmitter may have increased processing power and / or be able to calculate the flight time of the transmission between itself and the receiver. In this embodiment, the threshold to be met before the transmission of a signal to the receiver can be performed can be a difference in flight time, or a certain amount of difference, such as a change of at least 0.05ms, or a fraction of the transmission flight time, such as a change of at least 0.005%.

[0223] In other exemplary embodiments, the threshold value may be determined by the expectation of TDOA measurements. For example, a receiver may utilize TDOA measurements to determine the location of a UE, and a difference of at least 0.05 ms may be required in a subsequent time-of-flight calculation in order to process the resulting TDOA measurements, in which case the threshold value may be determined by the transmitter such that the difference between consecutively obtained TDOA measurements is no less than 0.05 ms.

[0224] As will be appreciated by those skilled in the art, other suitable thresholds may be used. Specifically, other factors may need to be considered when using the other techniques described above (such as RSRP measurements, Doppler shifts, or ground measurements) to verify the location of the UE. In these embodiments, appropriate thresholds determined by those skilled in the art and their technical understanding will be implemented based on the principles and concepts disclosed above. The above disclosure is not intended to be precisely limited to what has been disclosed, for example, other thresholds may be used in situations where the threshold is not precisely disclosed and has only one value. The thresholds may be implemented individually so that only one threshold needs to be met, or multiple thresholds may be implemented, in which case transmission is allowed only after each threshold is met, or only after a subset of the multiple thresholds implemented are met.

[0225] Those skilled in the art will further appreciate that such infrastructure equipment and / or communication devices as defined herein may be further defined according to the various arrangements and implementations discussed in the preceding paragraphs. Those skilled in the art will also appreciate that such infrastructure equipment and communication devices as defined and described herein may form part of a communication system other than the communication system defined in the present disclosure.

[0226] The following numbered paragraphs provide additional exemplary aspects and features of the present technology:

[0227] Paragraph 1. A method performed by a user equipment UE, the method comprising:

[0228] receiving a first signal from a non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network, the first signal being transmitted when the NTN infrastructure equipment is in a first orbital position,

[0229] determining a first measurement based on the received first signal,

[0230] receiving at least one further signal from the NTN infrastructure equipment at a time later than the time when the first signal was received, the at least one further signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location,

[0231] determining at least one further measurement based on the received at least one further signal, and

[0232] An indication for determining a relative difference between a determined first measurement and at least one further measurement is sent to the wireless communication network via a wireless access interface provided by the wireless communication network, for the wireless communication network to determine or verify the position of the UE based on the indication for determining a relative difference between the first measurement and at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at a first orbital position and one or more different orbital positions when the first signal and the at least one further signal are sent.

[0233] Paragraph 2. A method according to paragraph 1, wherein the first measurement and the at least one further measurement are measurements of an arrival time of a first signal relative to a previous signal and an arrival time of at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication of the relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival interval time measurements.

[0234] Paragraph 3. A method according to any one of paragraphs 1 or 2, wherein sending an indication of a relative difference between a determined first measurement and at least one other determined measurement to a wireless communication network comprises: sending an indication of the relative difference to the wireless communication network by the UE via radio resource control RRC or media access control MAC signaling.

[0235] Paragraph 4. A method according to any one of paragraphs 1, 2 or 3, wherein sending an indication to the wireless communication network for determining the relative difference between the determined first measurement and the determined at least one additional measurement includes: sending at a time after receiving the first signal and again at a time after receiving at least one additional signal, or sending only at a time after a group of signals including the first signal and one additional signal are received by the UE.

[0236] Paragraph 5. A method according to any of paragraphs 1 to 4, comprising: receiving an indication from the wireless communication network that the location of the UE must be verified as part of an RRC setup procedure.

[0237] Paragraph 6. A method according to any one of paragraphs 2 to 5, wherein sending an indication to the wireless communication network for determining a relative difference between the determined first measurement and at least one further determined measurement comprises: sending an arrival interval time measurement, at least one time difference between arrival interval time measurements and / or a flight time of communication between the NTN infrastructure equipment and the UE.

[0238] Paragraph 7. A method according to any one of paragraphs 1 to 6, comprising:

[0239] determining, by the UE, the position of the UE using a global navigation satellite system GNSS based on signals received by the UE from GNSS satellites or a terrestrial beacon system TBS based on signals received by the UE from TBS transmitters, and

[0240] The determined position of the UE is sent from the UE to the wireless communication network with an indication of a relative difference between the determined first measurement and the determined at least one further measurement.

[0241] Paragraph 8. A method performed by a user equipment UE, the method comprising:

[0242] sending a first reference signal to a NTN infrastructure device forming part of the wireless communication network via a wireless access interface of the wireless communication network formed by the NTN infrastructure device, the first reference signal being sent at a time determined according to a reference forming part of the wireless access interface, and the first reference signal being sent when the NTN infrastructure device is in a first orbital position,

[0243] at least one further reference signal is sent via the wireless access interface to the NTN infrastructure equipment at a time later than the time at which the first reference signal was sent, the at least one further reference signal being sent at a time determined based on a reference forming part of the wireless access interface, the at least one further signal being sent when the NTN infrastructure equipment is at one or more different orbital positions different from the first orbital position, a time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface being used by the wireless communication network to determine or verify the position of the UE based on measurements determined by the NTN infrastructure equipment, the time difference of arrival being caused by the NTN infrastructure equipment being at the first orbital position and the one or more different orbital positions when the first reference signal and the at least one further reference signal were sent.

[0244] Paragraph 9. The method according to paragraph 8, comprising:

[0245] An indication is received from the wireless communication network that the location of the UE must be verified as part of an RRC setup procedure.

[0246] Paragraph 10. A method according to paragraph 8 or 9, comprising:

[0247] determining, by the UE, the position of the UE using a global navigation satellite system GNSS based on signals received by the UE from GNSS satellites or a terrestrial beacon system TBS based on signals received by the UE from TBS transmitters, and

[0248] The determined location of the UE is sent from the UE to the wireless communication network.

[0249] Paragraph 11. A method according to paragraph 8, 9 or 10, comprising:

[0250] Receiving from the wireless communication network a timing advance for the UE to apply when transmitting to the NTN infrastructure equipment, and transmitting the first reference signal and at least one further reference signal to the NTN infrastructure equipment via the wireless access interface relative to a reference forming part of the wireless access interface comprises:

[0251] Transmitting the first reference signal and at least one further reference signal to the NTN infrastructure device includes adjusting a transmission time in the radio access interface relative to the reference to include a timing advance.

[0252] Paragraph 12. A method according to paragraph 11, wherein the UE performs one or more of the following: applying a timing advance to a first reference signal and at least one additional reference signal transmitted between the UE and the NTN infrastructure device; applying a timing advance when sending the first reference signal and at least one additional reference signal signaled by the wireless communication network to the UE; or determining a timing advance; applying the determined timing advance when sending the first reference signal and at least one additional reference signal; and signaling an indication of the timing advance applied by the UE to the wireless communication network.

[0253] Paragraph 13. A method of determining or verifying a location of a user equipment (UE), the method comprising:

[0254] receiving, at a non-terrestrial network NTN infrastructure device, from a UE a first reference signal transmitted via a radio access interface of a wireless communication network formed by the NTN infrastructure device, the first reference signal being received when the NTN infrastructure device is in a first orbital position,

[0255] determining a first measurement in accordance with a first reference signal, the first reference signal being sent at a time determined in accordance with a reference forming part of a wireless access interface,

[0256] receiving, at the NTN infrastructure equipment from the UE at a time later than the time of receiving the first reference signal, at least one further reference signal sent via the radio access interface, the at least one further reference signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location,

[0257] determining at least one further measurement in dependence upon at least one further reference signal, the at least one further reference signal being sent at a time relative to a reference forming part of the wireless access interface, or

[0258] determining a propagation time difference between the first reference signal and the at least one further reference signal based on the first measurement and the at least one further measurement, and determining, by the NTN infrastructure equipment, the position of the UE or verifying the position of the UE based on the determined propagation time difference between the first reference signal and the at least one further reference signal, or

[0259] The first measurement and the at least one further measurement are reported to the wireless communication network for use by the wireless communication network in determining the position of the UE or verifying the position of the UE based on a propagation time difference between the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at the first orbital position and at one or more different orbital positions when the first signal and the at least one further signal were transmitted.

[0260] Paragraph 14. A method according to paragraph 13, wherein determining the location of the UE or verifying the location comprises:

[0261] The location of the UE is determined by the NTN infrastructure equipment or is verified based on the determined propagation time difference of the UE.

[0262] Paragraph 15. A method according to paragraph 14, wherein determining the location of the UE or verifying the location comprises:

[0263] The location of the user equipment is reported to the wireless communication network through the wireless access interface.

[0264] Paragraph 16. The method of paragraph 15, comprising: comparing the location of the user equipment with the reported location of the user equipment, and reporting the comparison result to the wireless communication network.

[0265] Paragraph 17. A method according to paragraph 15, wherein the propagation time difference between the first reference signal and the at least one further reference signal is an uplink arrival time difference.

[0266] Paragraph 18. A method according to paragraph 13, wherein reporting the first measurement and at least one further measurement to the wireless communication network comprises:

[0267] The determined first measurement and the at least one further measurement are sent by the NTN infrastructure device to the wireless communication network.

[0268] Paragraph 19. A method according to paragraph 14, wherein reporting the first measurement and at least one additional measurement by the NTN infrastructure device to the wireless communication network includes: reporting the first measurement and at least one additional measurement to the wireless communication network after receiving the first reference signal and the at least one additional reference signal, or only after receiving a set of reference signals by the NTN infrastructure device.

[0269] Paragraph 20. A method according to paragraph 13, wherein reporting the first measurement and at least one additional measurement by the NTN infrastructure device to the wireless communication network includes: sending the first measurement and at least one additional measurement in one of the following forms: at least one arrival interval time of a signal at the NTN infrastructure device, at least one arrival interval time difference of a signal at the NTN infrastructure device, at least one round-trip time of communication between the NTN infrastructure device and the UE, and at least one flight time of communication between the NTN infrastructure device and the UE.

[0270] Paragraph 21. A method according to paragraph 13, wherein the first reference signal and the at least one further reference signal are received by the NTN infrastructure equipment after a timing advance is applied by the UE to the first reference signal and the at least one further reference signal.

[0271] Paragraph 22. A method according to paragraph 1, wherein the first measurement based on the received first signal and the at least one further measurement based on at least one further signal is one of: a measurement of a reference signal received power, a Doppler shift and / or a terrestrial network signal.

[0272] Paragraph 23. A method according to any of Paragraphs 1 to 22, wherein the NTN infrastructure equipment is located on a low earth orbit (LEO) or medium earth orbit (MEO) satellite.

[0273] Paragraph 24. A method according to any one of paragraphs 1 to 12, comprising:

[0274] receiving an indication of ephemeris information associated with at least one NTN infrastructure device from a wireless communication network, and

[0275] The location of the NTN infrastructure equipment is determined based on the indication of the ephemeris information.

[0276] Paragraph 25. A communication device comprising:

[0277] a transceiver circuit system configured to send signals to a wireless communication network via a wireless access interface provided by the wireless communication network, the wireless communication network comprising non-terrestrial network (NTN) infrastructure equipment, and to receive signals from the wireless communication network via the wireless access interface, and

[0278] a controller circuitry configured to control the transceiver circuitry:

[0279] receiving a first signal sent from the NTN infrastructure equipment via the wireless access interface, the first signal being sent when the NTN infrastructure equipment is in a first orbital position,

[0280] determining a first measurement based on the received first signal,

[0281] receiving, at a time later than the time at which the first signal is received, at least one further signal sent via the wireless access interface from the NTN infrastructure equipment, the at least one further signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location,

[0282] determining at least one further measurement based on the received at least one further signal, and

[0283] An indication for determining a relative difference between a determined first measurement and at least one further measurement is sent to the wireless communication network via a wireless access interface provided by the wireless communication network, for the wireless communication network to determine or verify the position of the UE based on the indication for determining a relative difference between the first measurement and at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at a first orbital position and one or more different orbital positions when the first signal and the at least one further signal are sent.

[0284] Paragraph 26. A communications apparatus according to paragraph 25, wherein the first measurement and the at least one further measurement are measurements of an arrival time of a first signal relative to a previous signal and an arrival time of at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication of the relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival interval time measurements.

[0285] Paragraph 27. A non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network, the infrastructure equipment comprising:

[0286] transceiver circuitry configured to receive signals from one or more communication devices transmitted via a wireless access interface provided by a wireless communication network including NTN infrastructure equipment, and to transmit signals to one or more communication devices transmitted via the wireless access interface, and

[0287] a controller circuitry configured to control the transceiver circuitry:

[0288] sending a first signal from an NTN infrastructure equipment forming part of a wireless communication network to a communication device and sending at least one further signal via a wireless access interface at a time later than the time of sending the first signal, the first signal and the at least one further signal being sent when the NTN infrastructure equipment is in different orbital locations,

[0289] Receiving from the communication device an indication for determining a relative difference between a first measurement based on the received first signal and at least one further measurement based on the received at least one further signal, for determining or verifying the position of the UE based on the indication for determining the relative difference between the first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at a first orbital position and at one or more different orbital positions when the first signal and the at least one further signal were sent.

[0290] Paragraph 28. NTN infrastructure equipment according to paragraph 27, wherein the first measurement and the at least one further measurement are measurements of an arrival time of a first signal relative to a previous signal and an arrival time of at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication of the relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival interval time measurements.

[0291] Paragraph 29. A communication device comprising:

[0292] a transceiver circuit system configured to send signals to a wireless communication network via a wireless access interface provided by the wireless communication network, the wireless communication network comprising non-terrestrial network (NTN) infrastructure equipment, and to receive signals from the wireless communication network via the wireless access interface, and

[0293] a controller circuitry configured to control the transceiver circuitry:

[0294] A first reference signal is sent via a wireless access interface to an NTN infrastructure device forming part of a wireless communication network, the first reference signal being sent at a time determined according to a reference forming part of the wireless access interface, and the first reference signal is sent when the NTN infrastructure device is in a first orbital position, at least one further reference signal is sent via the wireless access interface to the NTN infrastructure device at a time later than the time at which the first reference signal was sent, the at least one further reference signal being sent at a time determined according to the reference forming part of the wireless access interface, the at least one further signal being sent when the NTN infrastructure device is in one or more different orbital positions than the first orbital position, a time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface being used by the wireless communication network to determine or verify a position of the UE based on measurements determined by the NTN infrastructure device, the time difference of arrival being caused by the NTN infrastructure device being in the first orbital position and in the one or more different orbital positions when the first reference signal and the at least one further reference signal were sent.

[0295] Paragraph 30. A non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network for determining or verifying the location of a communication device, the infrastructure equipment comprising:

[0296] transceiver circuitry configured to receive signals from one or more communication devices transmitted via a wireless access interface provided by a wireless communication network including NTN infrastructure equipment, and to transmit signals from one or more communication devices transmitted via the wireless access interface, and

[0297] a controller circuitry configured to control the transceiver circuitry:

[0298] receiving, from the communication device, a first reference signal transmitted via the wireless access interface, the first signal being received when the NTN infrastructure equipment is at a first orbital position,

[0299] determining a first measurement in accordance with a first reference signal, the first reference signal being sent at a time determined in accordance with a reference forming part of a wireless access interface,

[0300] receiving, from the UE at a time later than the time of receiving the first reference signal, at least one further reference signal sent via the radio access interface, the at least one further reference signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location,

[0301] determining at least one further measurement in dependence upon at least one further reference signal, the at least one further reference signal being sent at a time relative to a reference forming part of the wireless access interface, or

[0302] determining a propagation time difference between the first reference signal and the at least one further reference signal based on the first measurement and the at least one further measurement, and determining, by the NTN infrastructure equipment, a position of the communication device or verifying a position of the UE based on the determined propagation time difference between the first reference signal and the at least one further reference signal, the determined propagation time difference being caused by the NTN infrastructure equipment being in the first orbital position and in one or more different orbital positions when the first signal and the at least one further signal were transmitted, or

[0303] The first measurement and at least one further measurement are reported to the wireless communication network for use by the wireless communication network in determining a position of the communication device or verifying the position of the communication device based on a propagation time difference between the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at a first orbital position and at one or more different orbital positions when the first signal and the at least one further signal were transmitted.

[0304] Paragraph 31. An apparatus forming part of a wireless communication network for determining or verifying the location of a communication device, the apparatus comprising processor circuitry configured to execute program code which, when executed, causes the processor circuitry to:

[0305] receiving a first measurement and at least one further measurement, the first measurement being a time difference relative to a reference forming part of a wireless access interface when a first signal is received by a non-terrestrial network, NTN, infrastructure equipment from the communication device, and the at least one further measurement being a time difference relative to a reference forming part of the wireless access interface when at least one further signal is received by the NTN infrastructure equipment from the communication device, the first signal and the at least one further signal being sent when the NTN infrastructure equipment is in different orbital positions, and

[0306] The position of the communication device is determined or verified based on a determined propagation time difference of the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at the first orbital position and at one or more different orbital positions when the first signal and the at least one further signal were transmitted.

[0307] Although the present disclosure has been described in conjunction with some embodiments, the present disclosure is not intended to be limited to the specific form set forth herein. In addition, although features may appear to be described in conjunction with specific embodiments, those skilled in the art will recognize that the various features of the described embodiments may be combined in any manner suitable for implementing the present technology.

[0308] References

[0309] [1]RP-220953. "NR NTN(Non-Terrestrial Networks)enhancements".RANplenary#95e.March 2022.

[0310] [2]RP-221013.《95e-25 email discussion

[0311] [3]RP-220139:Network verified UE location aspects; THALES

[0312] [4]RP-220174:Network verification ofUE location in NTN; QualcommIncorporated 79

[0313] [5]RP-220200:On Network-verified UE location for NR NTN;IntelCorporation

[0314] [6]RP-220421:Discussion on network-verified UE location for NR NTN;Huawei,HiSilicon

[0315] [7]R2-2101150Summary of[Post112-e]

[115] [NTN]the Email Discussion onLCS for NTN,Fraunhofer IIS,Fraunhofer HHI

[0316] [8]S3i210282

[0317] [9]R2 -2102679,Reply LS on UE location aspects in NTN.

[0318]

[10] R2-1913493UE positioning in legacy satellite communicationsystems for 5G NTN THALES

[0319]

[11] 3GPP TS 38.305V16.0.0(2020-03):3rd Generation PartnershipProject;Technical Specification Group Radio Access Network;NG Radio AccessNetwork(NG-RAN);Stage 2 functional specification of User Equipment(UE)positioning in NG-RAN(Release 16)

[0320]

[12] 3GPP TR38.821.“Solutions for NR to support non-terrestrialnetworks(NTN)”

[0321]

[13] TR 38.470.

[0322]

[14] 3GPP TR 22.926 Guidelines for Extraterritorial 5G Systems;Stage 1(Release 18)。

Claims

1. A method performed by a user equipment UE, the method comprising: receiving a first signal from a non-terrestrial network (NTN) infrastructure device forming part of a wireless communication network, the first signal being transmitted when the NTN infrastructure device is in a first orbital position, determining a first measurement based on the received first signal, receiving at least one further signal from the NTN infrastructure equipment at a time later than the time when the first signal is received, the at least one further signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location, determining at least one further measurement based on the received at least one further signal, and An indication for determining a relative difference between the determined first measurement and the determined at least one further measurement is sent to the wireless communication network via a wireless access interface provided by the wireless communication network, for the wireless communication network to determine or verify the position of the UE based on the indication for determining a relative difference between the first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at the first orbital position and the one or more different orbital positions when the first signal and the at least one further signal are sent.

2. The method according to claim 1, wherein: The first measurement and the at least one further measurement are measurements of an arrival time of the first signal relative to a previous signal and an arrival time of the at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication for determining a relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival inter-time measurements.

3. The method according to claim 1, wherein: Sending the indication of the relative difference between the determined first measurement and the determined at least one further measurement to the wireless communication network comprises sending the indication of the relative difference to the wireless communication network by the UE via Radio Resource Control, RRC, or Medium Access Control, MAC signaling.

4. The method according to claim 1, wherein: Sending the indication for determining the relative difference between the determined first measurement and the determined at least one further measurement to the wireless communication network comprises sending it at a time after receiving the first signal and again at a time after receiving the at least one further signal, or sending it only at a time after a group of signals including the first signal and one further signal are received by the UE.

5. The method according to claim 1, comprising: An indication is received from the wireless communication network that the location of the UE must be verified as part of an RRC setup procedure.

6. The method according to claim 2, wherein: Sending the indication for determining the relative difference between the determined first measurement and the determined at least one further measurement to the wireless communication network comprises sending the inter-arrival time measurement, at least one time difference between the inter-arrival time measurements and / or a flight time of communication between the NTN infrastructure equipment and the UE.

7. The method according to claim 1, comprising: determining, by the UE, a position of the UE using a global navigation satellite system GNSS according to signals received by the UE from GNSS satellites or a terrestrial beacon system TBS according to signals received by the UE from TBS transmitters, and The determined position of the UE is sent from the UE to the wireless communication network with the indication for determining a relative difference between the determined first measurement and the determined at least one further measurement.

8. A method performed by a user equipment UE, the method comprising: sending a first reference signal via a wireless access interface of a wireless communication network formed by non-terrestrial network (NTN) infrastructure equipment to said NTN infrastructure equipment forming part of said wireless communication network, said first reference signal being sent at a time determined according to a reference forming part of said wireless access interface and said first reference signal being sent when said NTN infrastructure equipment is in a first orbital position, sending, via the wireless access interface, at least one further reference signal to the NTN infrastructure equipment at a time later than the time at which the first reference signal was sent, the at least one further reference signal being sent at a time determined according to a reference forming part of the wireless access interface, the at least one further signal being sent when the NTN infrastructure equipment is in one or more different orbital positions than the first orbital position, a time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface being used by the wireless communication network to determine or verify the position of the UE based on measurements determined by the NTN infrastructure equipment, the time difference of arrival being caused by the NTN infrastructure equipment being in the first orbital position and the one or more different orbital positions when the first reference signal and the at least one further reference signal were sent.

9. The method according to claim 8, comprising: An indication is received from the wireless communication network that the location of the UE must be verified as part of an RRC setup procedure.

10. The method according to claim 8, comprising: determining, by the UE, a position of the UE using a global navigation satellite system GNSS according to signals received by the UE from GNSS satellites or a terrestrial beacon system TBS according to signals received by the UE from TBS transmitters, and The determined location of the UE is sent from the UE to the wireless communication network.

11. The method according to claim 8, comprising: Receiving from the wireless communication network a timing advance for the UE to apply when transmitting to the NTN infrastructure device, and transmitting the first reference signal and the at least one further reference signal to the NTN infrastructure device via the wireless access interface relative to the reference forming part of the wireless access interface comprises: Sending the first reference signal and the at least one further reference signal to the NTN infrastructure device comprises adjusting a transmission time in the radio access interface relative to the reference to include the timing advance.

12. The method according to claim 11, wherein: The UE performs one or more of the following: applying a timing advance to the first reference signal and the at least one further reference signal transmitted between the UE and the NTN infrastructure device; applying a timing advance when sending the first reference signal and the at least one further reference signal signaled by the wireless communication network to the UE; or determining a timing advance; applying the determined timing advance when sending the first reference signal and the at least one further reference signal; and signaling an indication of the timing advance applied by the UE to the wireless communication network.

13. A method for determining or verifying a location of a user equipment (UE), the method comprising: receiving, at a non-terrestrial network NTN infrastructure device, from the UE a first reference signal sent via a wireless access interface of a wireless communication network formed by the NTN infrastructure device, the first reference signal being received when the NTN infrastructure device is in a first orbital position, determining a first measurement in accordance with the first reference signal, the first reference signal being sent at a time determined in accordance with a reference forming part of the wireless access interface, receiving, at the NTN infrastructure equipment, from the UE at least one further reference signal sent via the radio access interface at a time later than the time of receiving the first reference signal, the at least one further reference signal being received when the NTN infrastructure equipment is at one or more different orbital locations than the first orbital location, determining at least one further measurement in dependence upon the at least one further reference signal, the at least one further reference signal being sent at a time relative to a reference forming part of the wireless access interface, or determining a propagation time difference between the first reference signal and the at least one further reference signal based on the first measurement and the at least one further measurement, and determining, by the NTN infrastructure device, the position of the UE or verifying the position of the UE based on the determined propagation time difference between the first reference signal and the at least one further reference signal, or reporting the first measurement and the at least one further measurement to the wireless communication network for use by the wireless communication network in determining the position of the UE or verifying the position of the UE based on a propagation time difference between the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at the first orbital position and the one or more different orbital positions when the first signal and the at least one further signal were sent.

14. The method according to claim 13, wherein: Determining the location of the UE or verifying the location includes: The location of the UE is determined by the NTN infrastructure equipment, or the location of the UE is verified based on the determined propagation time difference of the UE.

15. The method according to claim 14, wherein: Determining the location of the UE or verifying the location includes: The location of the user equipment is reported to the wireless communication network through the wireless access interface.

16. The method according to claim 15, comprising: The location of the user equipment is compared to the reported location of the user equipment and the comparison result is reported to the wireless communication network.

17. The method according to claim 15, wherein: The propagation time difference between the first reference signal and the at least one further reference signal is an uplink time difference of arrival.

18. The method according to claim 13, wherein: Reporting the first measurement and the at least one further measurement to the wireless communication network comprises: The determined first measurement and the at least one further measurement are sent by the NTN infrastructure device to the wireless communication network.

19. The method according to claim 14, wherein: Reporting the first measurement and the at least one further measurement by the NTN infrastructure device to the wireless communication network comprises reporting the first measurement and the at least one further measurement to the wireless communication network after receiving the first reference signal and the at least one further reference signal, or only after receiving a set of reference signals by the NTN infrastructure device.

20. The method according to claim 13, wherein: Reporting the first measurement and the at least one additional measurement by the NTN infrastructure device to the wireless communication network includes: sending the first measurement and the at least one additional measurement in one of the following forms: at least one inter-arrival time of a signal at the NTN infrastructure device, at least one inter-arrival time difference of the signal at the NTN infrastructure device, at least one round-trip time of communication between the NTN infrastructure device and the UE, and at least one flight time of communication between the NTN infrastructure device and the UE.

21. The method according to claim 13, wherein: The first reference signal and the at least one further reference signal are received by the NTN infrastructure device after applying a timing advance to the first reference signal and the at least one further reference signal by the UE.

22. The method according to claim 1, wherein: The first measurement based on the received first signal and the at least one further measurement based on the at least one further signal are one of: measurements of reference signal received power, Doppler shift and / or terrestrial network signals.

23. The method according to claim 1, wherein: The NTN infrastructure equipment is located on a low earth orbit LEO or medium earth orbit MEO satellite.

24. The method according to claim 1, comprising: receiving an indication of ephemeris information associated with at least one of the NTN infrastructure devices from the wireless communication network, and A location of the NTN infrastructure equipment is determined based on the indication of the ephemeris information.

25. A communication device, comprising: a transceiver circuit system configured to send signals to a wireless communication network via a wireless access interface provided by the wireless communication network, the wireless communication network comprising non-terrestrial network (NTN) infrastructure equipment, and to receive signals from the wireless communication network via the wireless access interface, and a controller circuit system configured to control the transceiver circuit system: receiving a first signal sent from the NTN infrastructure device via the wireless access interface, the first signal being sent when the NTN infrastructure device is in a first orbital position, determining a first measurement based on the received first signal, receiving, at a time later than the time of receiving the first signal, at least one further signal from the NTN infrastructure equipment sent via the wireless access interface, the at least one further signal being received when the NTN infrastructure equipment is at one or more different orbital locations different from the first orbital location, determining at least one further measurement based on the received at least one further signal, and An indication for determining a relative difference between the determined first measurement and the determined at least one further measurement is sent to the wireless communication network via a wireless access interface provided by the wireless communication network, for the wireless communication network to determine or verify the position of the UE based on the indication for determining a relative difference between the first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at the first orbital position and the one or more different orbital positions when the first signal and the at least one further signal are sent.

26. The communication device according to claim 25, wherein: The first measurement and the at least one further measurement are measurements of an arrival time of the first signal relative to a previous signal and an arrival time of the at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication for determining a relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival inter-time measurements.

27. A non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network, the infrastructure equipment comprising: transceiver circuitry configured to receive signals from one or more communication devices transmitted via a wireless access interface provided by a wireless communication network including the NTN infrastructure equipment, and to transmit signals to the one or more communication devices transmitted via the wireless access interface, and a controller circuit system configured to control the transceiver circuit system: sending a first signal from the NTN infrastructure equipment forming part of the wireless communication network to a communication device and sending at least one further signal via the wireless access interface at a time later than the time of sending the first signal, the first signal and the at least one further signal being sent when the NTN infrastructure equipment is in different orbital positions, receiving from the communication device an indication for determining a relative difference between a first measurement based on the received first signal and at least one further measurement based on at least one further signal received, for determining or verifying the position of the UE based on the indication for determining the relative difference between the first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at the first orbital position and one or more of the different orbital positions when the first signal and the at least one further signal were sent.

28. The NTN infrastructure equipment according to claim 27, wherein: The first measurement and the at least one further measurement are measurements of an arrival time of the first signal relative to a previous signal and an arrival time of the at least one further signal relative to at least the first signal, the first signal, the previous signal and the at least one further signal being sent by the NTN infrastructure equipment at known intervals, and the indication for determining a relative difference between the determined first measurement and the determined at least one further measurement is a downlink observed arrival time difference measurement of a difference of arrival inter-time measurements.

29. A communication device, comprising: a transceiver circuit system configured to send signals to a wireless communication network via a wireless access interface provided by the wireless communication network, the wireless communication network comprising non-terrestrial network (NTN) infrastructure equipment, and to receive signals from the wireless communication network via the wireless access interface, and a controller circuit system configured to control the transceiver circuit system: sending a first reference signal via the wireless access interface to the NTN infrastructure equipment forming part of the wireless communication network, the first reference signal being sent at a time determined according to a reference forming part of the wireless access interface and the first reference signal being sent when the NTN infrastructure equipment is in a first orbital position, at least one further reference signal is sent via the wireless access interface to the NTN infrastructure equipment at a time later than the time at which the first reference signal is sent, the at least one further reference signal being sent at a time determined according to a reference forming part of the wireless access interface, the at least one further signal being sent when the NTN infrastructure equipment is in one or more different orbital positions than the first orbital position, a time difference of arrival of the first reference signal and the at least one further reference signal relative to the reference of the wireless access interface being used by the wireless communication network to determine or verify the position of the UE based on measurements determined by the NTN infrastructure equipment, the time difference of arrival being caused by the NTN infrastructure equipment being in the first orbital position and the one or more different orbital positions when the first reference signal and the at least one further reference signal were sent.

30. Non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communications network for determining or verifying the location of a communications device, the infrastructure equipment comprising: transceiver circuitry configured to receive signals from one or more communication devices transmitted via a wireless access interface provided by a wireless communication network including the NTN infrastructure equipment, and to transmit signals from one or more communication devices transmitted via the wireless access interface, and a controller circuit system configured to control the transceiver circuit system: receiving, from a communication device, a first reference signal transmitted via the wireless access interface, the first signal being received when the NTN infrastructure equipment is in a first orbital position, determining a first measurement in accordance with the first reference signal, the first reference signal being sent at a time determined in accordance with a reference forming part of the wireless access interface, receiving, from a UE at a time later than the time of receiving the first reference signal, at least one further reference signal sent via the radio access interface, the at least one further reference signal being received when the NTN infrastructure equipment is in one or more different orbital locations than the first orbital location, determining at least one further measurement in dependence upon the at least one further reference signal, the at least one further reference signal being sent at a time relative to a reference forming part of the wireless access interface, or determining a propagation time difference between the first reference signal and the at least one further reference signal based on the first measurement and the at least one further measurement, and determining, by the NTN infrastructure equipment, a position of the communication device or verifying a position of the UE based on the determined propagation time difference between the first reference signal and the at least one further reference signal, the determined propagation time difference being caused by the NTN infrastructure equipment being in the first orbital position and the one or more different orbital positions when the first signal and the at least one further signal were transmitted, or reporting the first measurement and the at least one further measurement to the wireless communication network for use by the wireless communication network in determining a position of the communication device or verifying a position of the communication device based on a propagation time difference between the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at the first orbital position and at least one of the different orbital positions when the first signal and the at least one further signal were transmitted.

31. An apparatus forming part of a wireless communication network for determining or verifying the location of a communication device, the apparatus comprising processor circuitry configured to execute program code which when executed causes the processor circuitry to: receiving a first measurement and at least one further measurement, the first measurement being a time difference relative to a reference forming part of a wireless access interface when a first signal is received by a non-terrestrial network (NTN) infrastructure equipment from the communication device, and the at least one further measurement being a time difference relative to a reference forming part of the wireless access interface when at least one further signal is received by the NTN infrastructure equipment from the communication device, the first signal and the at least one further signal being sent when the NTN infrastructure equipment is in different orbital positions, and The position of the communication device is determined or verified based on a determined propagation time difference of the first reference signal and the at least one further reference signal, the propagation time difference being caused by the NTN infrastructure equipment being at the first orbital position and at one or more of the different orbital positions when the first signal and the at least one further signal were sent.

32. A method for determining or verifying a location of a user equipment (UE), the method comprising: sending a first signal from a non-terrestrial network (NTN) infrastructure equipment forming part of a wireless communication network to a communication device and sending at least one further signal via a wireless access interface at a time later than the time of sending the first signal, the first signal and the at least one further signal being sent when the NTN infrastructure equipment is in different orbital positions, receiving from the communication device an indication for determining a relative difference between a first measurement based on the received first signal and at least one further measurement based on at least one further signal received, for determining or verifying the position of the UE based on the indication for determining the relative difference between the first measurement and the at least one further measurement, the relative difference being caused by the NTN infrastructure equipment being at the first orbital position and at one or more of the different orbital positions when the first signal and the at least one further signal were sent.

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