Determination of RTT for UE location for network verification

Abstract

The present disclosure relates to a network device for a non-terrestrial network, and a corresponding method for a network device. More specifically, a network device comprises a transceiver and circuitry to obtain an estimated round trip time (RTT) for a location of a user equipment (UE), where the obtaining of the RTT is based on (i) a user equipment (UE) Rx-Tx time difference, which is a difference between a reception timing of a subframe boundary in a downlink frame of the UE and a transmission timing of a subframe boundary in an uplink frame of the UE, the present invention relates to a method for transmitting a transmission timing, which is the closest in time to a subframe received by a UE, (ii) a gNB Rx-Tx time difference, which is the difference between a reception timing of a subframe boundary in a downlink frame of a gNB and a transmission timing of a subframe boundary in an uplink frame of the gNB, which is the closest in time to a subframe received by the gNB, (iii) Timing Advance (TA) information of the UE, and (iii) Rx-Tx time difference, which is the difference between the reception timing of the subframe boundary in the downlink frame of the gNB and the transmission timing of the subframe boundary in the uplink frame of the gNB, which is the closest in time to the subframe received by the gNB. The TA information indicates a rounded value of a timing advance value, and (iv) a correction of the timing advance TA information.

Description

Technical Field

[0001] The present invention relates to the transmission of system information related to non-terrestrial networks. In particular, the present invention relates to an apparatus and method for generating, signaling, receiving and / or utilizing system information related to non-terrestrial networks. Background Art

[0002] Currently, the 3rd Generation Partnership Project (3GPP) is working on the technical specifications for the next generation of cellular technology, also known as fifth generation (5G).

[0003] One goal is to provide a single technical framework that addresses all use cases, requirements, and deployment scenarios (e.g., see Section 6 of 3GPP TR 38.913 Version 16.0.0), including at least enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). For example, eMBB deployment scenarios may include indoor hotspots, dense urban, rural, urban macro, and high-speed; URLLC deployment scenarios may include industrial control systems, mobile health (remote monitoring, diagnosis, and treatment), real-time vehicle control, and wide-area monitoring and control systems for smart grids; and mMTC deployment scenarios may include scenarios with a large number of non-time-critical data transmission devices, such as smart wearables and sensor networks. Services for eMBB and URLLC are similar in that they both require very wide bandwidth, but differ in that URLLC services may preferably require ultra-low latency.

[0004] The second goal is to achieve forward compatibility. Backward compatibility with Long Term Evolution (LTE, LTE-A) cellular systems is not required, which facilitates completely new system designs and / or the introduction of new features.

[0005] A notable feature of 5G is the introduction of non-terrestrial networks (NTNs), which include satellites in the communication path between user equipment and the network. Summary of the Invention

[0006] One non-limiting and exemplary embodiment facilitates efficient transmission and reception of system information related to a non-terrestrial network.

[0007] In one embodiment, the technology disclosed herein features a network device comprising: a transceiver and circuitry that obtains an estimated round trip time (RTT) for a location of a user equipment (UE), wherein the RTT is obtained based on (i) a user equipment (UE) Rx-Tx time difference, which is a difference between a receive timing of a subframe boundary in a downlink frame of the UE and a transmit timing of a subframe boundary in an uplink frame of the UE, the transmit timing being closest in time to a subframe received by the UE, (ii) a gNBRx-Tx time difference, which is a difference between a receive timing of a subframe boundary in a downlink frame of a gNB and a transmit timing of a subframe boundary in an uplink frame of the gNB, the transmit timing being closest in time to a subframe received by the gNB, (iii) timing advance (TA) information of the UE, the TA information indicating a rounded value of a timing advance value, and (iv) a correction of the timing advance (TA) information.

[0008] It should be noted that the general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0009] Additional benefits and advantages of the disclosed embodiments will become apparent from the description and drawings. Benefits and / or advantages may be obtained individually from the various embodiments and features of the description and drawings, and these embodiments and features do not need to be provided in full in order to obtain one or more such benefits and / or advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Hereinafter, exemplary embodiments are described in more detail with reference to the accompanying drawings and figures.

[0011] Figure 1 An exemplary architecture of a 3GPP NR system is shown.

[0012] Figure 2 Figure 2 is a schematic diagram showing the functional division between NG-RAN and 5GC.

[0013] Figure 3 It is a sequence diagram of the RRC connection establishment / reconfiguration process.

[0014] Figure 4 is a schematic diagram illustrating usage scenarios of enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low-latency communication (URLLC).

[0015] Figure 5 is a block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario.

[0016] Figure 6 An exemplary transparent satellite-based NG RAN architecture is shown.

[0017] Figure 7 An exemplary NG RAN architecture based on regenerative satellites is shown.

[0018] Figure 8 An exemplary scenario is shown where several UEs are served by a satellite.

[0019] Figure 9 An exemplary NTN setup is shown where the satellite moves at a certain speed.

[0020] Figure 10 is a block diagram illustrating an exemplary structure of a user device and a network device.

[0021] Figure 11 The timing of transmitting and receiving DL-PRS and UL-SRS is shown.

[0022] Figure 12 is a schematic diagram showing the timing of subframes transmitted and received by a gNB or UE.

[0023] Figure 13 is a diagram illustrating a first exemplary correction of RTT based on the timing of subframes transmitted and received by a gNB or a UE.

[0024] Figure 14 is a diagram illustrating a second exemplary correction of RTT based on the timing of subframes transmitted and received by a gNB or a UE.

[0025] Figure 15 The timing of sending DL-PRS from the gNB to the UE via satellite is shown.

[0026] Figure 16 The SRS-config sent from the gNB to the UE via satellite and the timing of the UL-SRS sent from the UE to the gNB via satellite are shown.

[0027] Figure 17 is a schematic diagram illustrating a first example of the first exemplary embodiment, wherein a UE Rx-Tx difference and a TA report are received from a UE, and a gNB Rx-Tx difference is received from a gNB.

[0028] Figure 18 is a schematic diagram illustrating a second example of the first exemplary embodiment, wherein a UE Rx-Tx difference and a TA report are received from a UE, and a gNB Rx-Tx difference is received from a gNB.

[0029] Figure 19 is a schematic diagram illustrating a first example of the second exemplary embodiment, wherein a UE Rx-Tx difference and a TA report are received from a UE, and a gNB Rx-Tx difference and a K_offset are received from a gNB.

[0030] Figure 20 is a schematic diagram illustrating a second example of the second exemplary embodiment, wherein a UE Rx-Tx difference and a TA report are received from a UE, and a gNB Rx-Tx difference and a K_offset are received from a gNB.

[0031] Figure 21 is a schematic diagram illustrating a first example of the fourth exemplary embodiment, wherein a corrected UE Rx-Tx difference is received from the UE and a gNB Rx-Tx difference is received from the gNB.

[0032] Figure 22 is a schematic diagram illustrating a second example of the fourth exemplary embodiment, wherein a corrected UE Rx-Tx difference is received from the UE, and a corrected gNB Rx-Tx difference is received from the gNB.

[0033] Figure 23 is a schematic diagram illustrating a first example of the fifth exemplary embodiment, wherein a UE Rx-Tx difference and corrected TA information are received from a UE, and a gNB Rx-Tx difference is received from a gNB.

[0034] Figure 24 is a schematic diagram illustrating a second example of the fifth exemplary embodiment, wherein a UE Rx-Tx difference and corrected TA information are received from a UE, and a corrected gNB Rx-Tx difference is received from a gNB.

[0035] Figure 25 is a schematic diagram illustrating a first example of the third exemplary embodiment, wherein a UE Rx-Tx difference and TA report is received from a UE, and a gNB Rx-Tx difference and TA report is received from a gNB.

[0036] Figure 26 is a schematic diagram illustrating a second example of the third exemplary embodiment, wherein a UE Rx-Tx difference and TA report is received from a UE, and a gNB Rx-Tx difference and TA report is received from a gNB.

[0037] Figure 27 is a schematic diagram illustrating a sixth exemplary embodiment, wherein a UE Rx-Tx difference, a TA report, and a gNB Rx-Tx difference are received from a gNB.

[0038] Figure 28 is a schematic diagram illustrating a seventh exemplary embodiment, in which the UE Rx-Tx difference, TA report, and gNB Rx-Tx difference are processed by the gNB, and the RTT is received from the gNB.

[0039] Figure 29is a schematic diagram illustrating an eighth exemplary embodiment, in which a corrected UE Rx-Tx difference and a gNB Rx-Tx difference are received from a gNB.

[0040] Figure 30 is a flow chart illustrating steps for verifying the location of a UE based on a location estimate, where the location estimate is based on RTT measurements. DETAILED DESCRIPTION

[0041] 5G NR system architecture and protocol stack

[0042] 3GPP has been working on the next version of fifth-generation cellular technology, known as 5G, including the development of new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for continued 5G NR standard-compliant trials and commercial deployments of smartphones.

[0043] The overall system architecture assumes an NG-RAN (Next Generation Radio Access Network) including gNBs, which provide NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol terminations to the UE. The gNBs are interconnected with each other via the Xn interface. The gNBs are also connected to the NGC (Next Generation Core) via the Next Generation (NG) interface, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity that implements the AMF) via the NG-C interface, and to the UPF (User Plane Function) (e.g., a specific core entity that implements the UPF) via the NG-U interface. The NG-RAN architecture is illustrated in Figure 1 (see, for example, 3GPP TS 38.300 v16.3.0, section 4).

[0044] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, Section 4.4.1) consists of the PDCP (Packet Data Convergence Protocol, see Section 6.4 of TS 38.300), the RLC (Radio Link Control, see Section 6.3 of TS 38.300), and the MAC (Medium Access Control, see Section 6.2 of TS 38.300) sublayers, which terminate in the gNB on the network side. In addition, a new Access Stratum (AS) sublayer (SDAP, Service Data Adaptation Protocol) is introduced above PDCP (see, for example, 3GPP TS 38.300, Subclause 6.5). A control plane protocol stack is also defined for NR (see, for example, TS 38.300, Section 4.4.2). An overview of Layer 2 functionality is provided in Subclause 6 of TS 38.300. The RRC layer functionality is outlined in Subclause 7 of TS 38.300.

[0045] For example, the medium access control layer handles logical channel multiplexing as well as scheduling and scheduling-related functions, including handling different parameter sets.

[0046] The physical layer (PHY) is responsible for, for example, decoding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. It also handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for the transmission of a specific transport channel, and each transport channel is mapped to a corresponding physical channel. Examples of physical channels are the PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) for the uplink, and the PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) for the downlink.

[0047] NR use cases and deployment scenarios can include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC), each with distinct requirements regarding data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps downlink and 10 Gbps uplink) and user-experienced data rates approximately three times those offered by IMT-Advanced. URLLC, on the other hand, places stricter requirements on ultra-low latency (0.5 ms for both UL and DL user plane latency) and high reliability (1-10-5 within 1 ms). Finally, mMTC may favor high connection density (1,000,000 devices / km2 in urban environments), extensive coverage in harsh environments, and extremely long battery life (15 years) for low-cost devices.

[0048] Therefore, a set of OFDM parameters (e.g., subcarrier spacing, OFDM symbol duration, cyclic prefix (CP) duration, number of symbols per scheduling interval) that is suitable for one use case may not be well-suited for another. For example, compared to mMTC services, low-latency services may prefer shorter symbol durations (and therefore larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI). Furthermore, deployment scenarios with large channel delay spread may prefer longer CP durations than those with short delay spread. Subcarrier spacing should be optimized accordingly to maintain similar CP overhead. NR can support more than one subcarrier spacing value. Accordingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, and so on are currently under consideration. Symbol duration Tu and subcarrier spacing Δf are directly related by the formula Δf = 1 / Tu. In a manner similar to that in LTE systems, the term "resource element" can be used to refer to the smallest resource unit consisting of one subcarrier, the length of one OFDM / SC-FDMA symbol.

[0049] In the new radio system 5G-NR, for each numerology set and carrier, a resource grid of subcarriers and OFDM symbols is defined for the uplink and downlink, respectively. Each element in the resource grid is called a resource element and is identified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v16.3.0, e.g., Section 4). For example, downlink and uplink transmissions are organized into frames with a duration of 10 ms, each consisting of ten subframes of 1 ms duration. In 5G NR implementations, the number of consecutive OFDM symbols per subframe depends on the subcarrier spacing configuration. For example, for a 15 kHz subcarrier spacing, a subframe has 14 OFDM symbols (similar to LTE-compliant implementations, assuming a normal cyclic prefix). On the other hand, for a 30 kHz subcarrier spacing, a subframe has two slots, each containing 14 OFDM symbols.

[0050] 5G NR functional division between NG-RAN and 5GC

[0051] Figure 2 This example illustrates the functional division between NG-RAN and 5GC. The NG-RAN logical node is the gNB or ng-eNB. The 5GC has the logical nodes AMF, UPF, and SMF.

[0052] In particular, gNB and ng-eNB host the following key functions:

[0053] - Functions for radio resource management, such as radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to UEs in both uplink and downlink (scheduling);

[0054] - IP header compression, encryption and integrity protection of data;

[0055] - Select the AMF at UE attach when the route to the AMF cannot be determined from the information provided by the UE;

[0056] - Routing of user plane data towards UPF(s);

[0057] - Routing of control plane information to the AMF;

[0058] - Connection establishment and release;

[0059] - Scheduling and transmission of paging messages;

[0060] - Scheduling and transmission of system broadcast information (from AMF or OAM);

[0061] - Measurement and measurement reporting configuration for mobility and scheduling;

[0062] - Transport level packet marking in uplink;

[0063] - Session management;

[0064] - Network slicing support;

[0065] - QoS flow management and mapping to data radio bearers;

[0066] - Support for UEs in RRC_INACTIVE state;

[0067] - NAS message distribution function;

[0068] - Radio access network sharing;

[0069] - Dual connectivity;

[0070] - Tight interworking between NR and E-UTRA.

[0071] The Access and Mobility Management Function (AMF) hosts the following main functions:

[0072] - Non-access stratum NAS signaling termination;

[0073] - NAS signaling security;

[0074] - Access layer AS security control;

[0075] - Intra-core network CN node signalling for mobility between 3GPP access networks;

[0076] - Idle mode UE reachability (including control and execution of paging retransmissions);

[0077] - Registration area management;

[0078] - Support for intra-system and inter-system mobility;

[0079] - Access authentication;

[0080] - Access authorization, including roaming rights checks;

[0081] - Mobility management control (subscription and policy);

[0082] - Network slicing support;

[0083] - Session Management Function SMF selection.

[0084] Additionally, the User Plane Function (UPF) hosts the following key functions:

[0085] - Anchor point for intra / inter-RAT mobility (when applicable);

[0086] - External PDU session point interconnected with the data network;

[0087] - Packet routing and forwarding;

[0088] - Packet inspection and user plane parts of policy rule enforcement;

[0089] - Data usage report;

[0090] - Uplink classifier that supports routing traffic flows to the data network;

[0091] - Support branch points for multi-homed PDU sessions;

[0092] - User plane QoS processing, such as packet filtering, gating, UL / DL rate enforcement;

[0093] - Uplink information flow verification (SDF to QoS flow mapping);

[0094] - Downlink packet buffering and downlink data notification triggering.

[0095] Finally, the session management function SMF hosts the following main functions:

[0096] - Session management;

[0097] - UE IP address allocation and management;

[0098] - Selection and control of UP function;

[0099] - Configure traffic steering at the User Plane Function (UPF) to route traffic to the appropriate destination;

[0100] - Policy implementation and QoS control part;

[0101] - Downlink data notification.

[0102] In addition, the 5GC may include a location management function (LMF), which includes the following functions:

[0103] - Support UE location determination;

[0104] - Obtain downlink position measurements or position estimates from the UE;

[0105] - Obtain uplink position measurements from NG RAN;

[0106] - Obtain non-UE-associated assistance data from NG RAN;

[0107] - Provide broadcast assistance data to the UE and forward the associated encryption keys to the AMF.

[0108] RRC connection establishment and reconfiguration process

[0109] Figure 3 Illustrate some interactions between the UE, gNB and AMF (5GC entity) in the context of the UE transitioning from RRC_IDLE to RRC_CONNECTED for the NAS part (see TS 38.300).

[0110] RRC is the higher-layer signaling (protocol) used for UE and gNB configuration. Specifically, the transition involves the AMF preparing UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sending it to the gNB along with an Initial Context Setup Request (INITIAL CONTEXT SETUP REQUEST). The gNB then activates AS security with the UE by sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message to the gNB. The gNB then reconfigures the UE to set up Signaling Radio Bearer 2 (SRB2) and one or more Data Radio Bearers (DRBs) by sending an RRCReconfiguration message to the UE, and receiving an RRCReconfigurationComplete message from the UE in response. For signaling-only connections, the steps related to RRCReconfiguration are skipped because SRB2 and DRBs are not set up. Finally, the gNB notifies the AMF of the completion of the setup process with an Initial Context Setup Response (INITIAL CONTEXT SETUP RESPONSE).

[0111] Therefore, the present disclosure provides a fifth generation core (5GC) entity (e.g., AMF, SMF, etc.), which includes a control circuit and a transmitter. The control circuit operates to establish a next generation (NG) connection with a gNB. The transmitter operates to send an initial context setup message to the gNB via the NG connection, thereby initiating the establishment of a signaling radio bearer between the gNB and a user equipment (UE). Specifically, the gNB sends radio resource control (RRC) signaling including a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation configuration.

[0112] IMT usage scenarios in 2020 and beyond

[0113] Figure 4 This section illustrates some use cases for 5G NR. Consider three use cases envisioned by IMT-2020 to support a wide variety of services and applications within the 3rd Generation Partnership Project New Radio (3GPP NR). Phase 1 specifications for enhanced mobile broadband (eMBB) have already been included. In addition to further expanding eMBB support, current and future work will also address the standardization of ultra-reliable low-latency communications (URLLC) and massive machine-type communications. Figure 4 Some examples of envisaged usage scenarios for IMT for 2020 and beyond are shown (see for example ITU-R M.20183 Figure 2).

[0114] URLLC use cases have stringent requirements for capabilities such as throughput, latency, and availability, and are envisioned as an enabler for future vertical applications such as wireless control of industrial manufacturing or production processes, remote medical surgery, distribution automation in smart grids, and transportation safety. Ultra-reliability in URLLC will be supported by identifying technologies that meet the requirements set by TR 38.913 version 16.0.0. For NR URLLC in Release 15, key requirements include a target user plane latency of 0.5 ms for the UL (uplink) and 0.5 ms for the DL (downlink). The general URLLC requirement for a single transmission of a packet is a BLER (block error rate) of 1E-5 for a 32-byte packet size, with a user plane latency of 1 ms.

[0115] From a physical layer perspective, reliability can be improved in a variety of possible ways. Current approaches to improving reliability include defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, and more. However, as NR becomes more stable and developed (a key requirement for NR URLLC), the scope for achieving ultra-reliability is likely to broaden. Specific use cases for NR URLLC in Rel. 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0116] In addition, the technical enhancements targeted by NR URLLC are aimed at latency improvement and reliability improvement. The technical enhancements for latency improvement include a configurable parameter set, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition for data channels, and downlink preemption. Preemption means stopping the transmission for which resources have been allocated, and the allocated resources are used for another transmission that has been requested later, but has lower latency / higher priority requirements. Thus, the already authorized transmission is preempted by the later transmission. Preemption can be applied independently of the specific service type. For example, a transmission for service type A (URLLC) can be used to preempt transmissions for service type B (such as eMBB). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0117] The mMTC (Massive Machine Type Communication) use case is characterized by a very large number of connected devices, often transmitting relatively small amounts of non-latency-sensitive data. This requires low-cost devices with very long battery life. From a NR perspective, utilizing very narrow bandwidth segments is a potential solution for UEs to conserve power and achieve long battery life.

[0118] As mentioned above, the scope of reliability in NR is expected to broaden. A key requirement in all cases, particularly necessary for URLLC and mMTC, is high or ultra-reliability. Several mechanisms can be considered to improve reliability from both a radio and network perspective. Generally, there are several key potential areas that can help improve reliability. These include compact control channel information, data / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability, regardless of the specific communication scenario.

[0119] For NR URLLC, other use cases with more stringent requirements have been identified, such as factory automation, transportation industry, and power distribution. The more stringent requirements are higher reliability (up to 106 level), higher availability, packet size up to 256 bytes, time synchronization down to the order of a few μs, where the value can be 1 μs or several μs depending on the frequency range, and short latency of about 0.5 to 1 ms depending on the use case, in particular a target user plane latency of 0.5 ms.

[0120] Furthermore, several technical enhancements from a physical layer perspective have been identified for NR URLLC. These include PDCCH (Physical Downlink Control Channel) enhancements related to compact DCI, PDCCH repetition, and increased PDCCH monitoring. Furthermore, UCI (Uplink Control Information) enhancements are related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback enhancements. Furthermore, PUSCH enhancements have been identified related to mini-slot-level hopping and retransmission / repetition enhancements. The term "mini-slot" refers to a transmission time interval (TTI) that includes fewer symbols than a slot (a slot consisting of fourteen symbols).

[0121] QoS control

[0122] The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed bit rate (GBR QoS flows) and QoS flows that do not (non-GBR QoS flows). At the NAS level, QoS flows are the finest granularity for QoS differentiation within a PDU session. QoS flows are identified within a PDU session by a QoS Flow ID (QFI) carried in the encapsulation header on the NG-U interface.

[0123] For each UE, the 5GC establishes one or more PDU Sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) together with the PDU Session and may subsequently configure (up to NG-RAN when to do so) additional DRBs for the QoS Flow(s) of that PDU Session, e.g. as described above with reference to Figure 3 As shown in Figure 2, NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0124] Figure 5 The 5G NR non-roaming reference architecture is illustrated (see TS 23.501 v16.6.0, section 4.2.3). Figure 4 The example application function (AF) described in [1] (e.g., an external application server hosting 5G services) interacts with the 3GPP core network to provide services, such as supporting application influence on traffic routing, accessing the network exposure function (NEF), or interacting with the policy framework for policy control (see Policy Control Function, PCF), such as QoS control. Based on operator deployment, application functions deemed trusted by the operator may be allowed to interact directly with relevant network functions. Application functions that are not allowed to directly access network functions by the operator may interact with relevant network functions using the external exposure framework via the NEF.

[0125] Figure 5 The figure shows other functional units of the 5G architecture, namely the network slice selection function (NSSF), network repository function (NRF), unified data management (UDM), authentication server function (AUSF), access and mobility management function (AMF), session management function (SMF) and data network (DN), such as operator services, Internet access or third-party services. All or part of the core network functions and application services can be deployed and run in a cloud computing environment.

[0126] Therefore, in the present disclosure, an application server (e.g., AF of a 5G architecture) is provided, the application server including a transmitter and a control circuit, the transmitter in operation sending a request including QoS requirements of at least one of URLLC, eMBB, and mMTC services to at least one of functions of 5GC (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to establish a PDU session including a radio bearer between a gNB and a UE according to the QoS requirements, and the control circuit in operation using the established PDU session to perform the service.

[0127] System information transmission

[0128] System information is a downlink broadcast message periodically transmitted by base stations (gNBs in 5G, generally network nodes). It contains information used by UEs to establish connections with base stations. In 5G, UEs read system information for cell camping at power-up and for cell selection and reselection when in RRC_IDLE mode. System information provides all necessary details, such as system frame number, system bandwidth, PLMN, cell selection and reselection thresholds, to access the network.

[0129] System information consists of a Master Information Block (MIB) and a System Information Block (SIB). The SIB contains various information. Relevant to this disclosure may be information related to NTN transmission, as described below. MIB information is transmitted (broadcasted) via the BCH and PBCH channels, while SIB information is transmitted via the DL-SCH and PDSCH channels.

[0130] Typically, system information can be transmitted periodically (so that newly connected terminals can obtain it) or on demand. The periodic scheduling of system information transmission can be configured by RRC. Specifically, SIB1 (referenced by MIB) carries scheduling information, which specifies, for example, the system information window (the repetition period of the system information transmission pattern), some transmission parameters for receiving system information (such as physical layer parameters), and the mapping of SIBs within the system information window (transmission pattern).

[0131] Non-terrestrial Network (NTN)

[0132] Due to its wide service coverage capabilities and reduced vulnerability of space / air vehicles to physical attacks and natural disasters, NTN can facilitate the deployment of NR services in unserved areas (e.g., isolated or remote areas, aircraft or ships) and underserved areas (e.g., suburban and rural areas) that are not covered by terrestrial NR networks. Furthermore, NTN can enhance the reliability of NR services by providing service continuity for passengers on mobile platforms or ensuring service availability anywhere, especially for critical communications.

[0133] Benefits may involve operating a standalone non-terrestrial network or an integrated terrestrial and non-terrestrial network, which may impact coverage, user bandwidth, system capacity, service reliability or availability.

[0134] A non-terrestrial network refers to a network or network segment that uses, for example, RF resources on a satellite. An NTN typically features the following system elements: an NTN terminal, which can be a 3GPP UE or a satellite-specific terminal if the satellite does not directly serve the 3GPP UE; a serving link, which is the radio link between the user equipment and the space / airborne platform; an airborne platform carrying the payload; a gateway connecting the space / airborne platform to the core network; and a feeder link, which is the radio link between the gateway and the space / airborne platform.

[0135] In 3GPP, NR-based operations in non-terrestrial networks (NTN) are studied and described (e.g., see 3GPP TR 38.811, New Radio (NR) Studies for Support of Non-terrestrial Networks, Release 15.4.0, and 3GPP TR 38.821, NR Solutions for Support of Non-terrestrial Networks, Release 16.0.0).

[0136] Non-terrestrial networks (NTNs) are networks or network segments that use RF resources over air or space entities for transmission, such as:

[0137] Space launch vehicles: Satellites (including low Earth orbit (LEO) satellites, medium Earth orbit (MEO) satellites, geosynchronous Earth orbit (GEO) satellites, and highly elliptical orbit (HEO) satellites)

[0138] Aerial vehicles: High altitude platforms (HAPs), including unmanned aircraft systems (UAS), including lighter-than-UAS aviation (LTA), heavier-than-UAS aviation (HTA), all aircraft typically operating at altitudes between 8 and 50 km, in a quasi-stationary state.

[0139] Exemplarily, a UAS or satellite platform connects to a 5G network via one or more gateways linked to a data network. The NTN may include the following system elements: NTN-capable terminals, which may refer to 3GPP UEs or terminals dedicated to satellite systems if the satellite does not directly serve 3GPP UEs; service links, which refer to the radio links between user equipment and the space / air platform; the air platform carrying the payload; a gateway connecting the space / air platform to the core network; and feeder links, which refer to the radio links between the gateway-centric space / air platform. The platform may implement transparent or regenerative payload transport, with the following exemplary features.

[0140] · In transparent payload, the platform acts as a repeater by filtering, converting and amplifying the wave signal while the payload remains unchanged.

[0141] In a regenerative payload, the platform has some or all of the base station functionality. In addition to RF filtering, conversion, and amplification, it can also perform demodulation / modulation, switching / routing, and encoding / decoding.

[0142] Inter-satellite links (ISLs) can be optionally used to form satellite constellations. ISLs (Inter-satellite Links) are transmission links between satellites.

[0143] Figure 6This illustrates a non-terrestrial network scenario, where transmissions between terminals (UEs) occur via a remote radio unit (RRU) consisting of a satellite and an NTN gateway. The gNB, located at the gateway, acts as a dispatching device. The satellite payload implements frequency conversion and RF amplification in both the uplink and downlink directions. Thus, the satellite relays the NR radio interface from the feeder link (between the NTN gateway and the satellite) to the serving link (between the satellite and the UE), and vice versa. The satellite radio interface (SRI) on the feeder link is NR-Uu. In other words, the satellite does not terminate NR-Uu. Satellites in this configuration are referred to as transparent satellites.

[0144] Figure 7 This illustrates a non-terrestrial network scenario, where transmissions between terminals (UEs) occur via satellites, including a gNB as a dispatching device. Satellites in this configuration are called regenerative satellites. According to one exemplary embodiment (see Section 5.2 of TR 38.321), the NG-RAN logical architecture described in TS 38.401 is used as a baseline for the NTN scenario. The satellite payload regenerates signals received from Earth. The NR-Uu radio interface is located on the serving link between the UE and the satellite. The satellite radio interface (SRI) is located on the feeder link between the NTN gateway and the satellite. The SRI (satellite radio interface) is the transmission link between the NTN gateway and the satellite.

[0145] Figure 8 An example scenario is shown where three UEs (UE1, UE2, and UE3) are served by satellite S1. Satellite S1 communicates with the gNB and NTN gateway via a feeder link, and with another neighboring satellite S2 via an inter-satellite link.

[0146] There are different types of satellites providing communications: low-Earth orbit (LEO) or geosynchronous orbit (GEO) (also known as geostationary orbit) satellites. Geosynchronous satellites appear stationary because they move at the same angular velocity as the Earth and follow a path parallel to the Earth's rotation, providing coverage for a specific area. From land, GEO satellites appear stationary. LEO satellites orbit at altitudes between 160 and 2,000 kilometers (99 and 1,200 miles). As the satellites move, LEO satellites can provide continuous global coverage. Unlike GEO satellites, LEO satellites also travel much faster because they are closer to the Earth.

[0147] GEO satellites have many applications, including weather forecasting, satellite radio, and television. However, because GEO satellites operate at such high altitudes, signals experience long communication lags (delays) as they travel between them. Therefore, many important communications are conducted via LEO satellite networks, which allow for faster connections without wires or cables.

[0148] However, in general, there may be various types of platforms in the NTN, including not only satellites but also UAS (Unmanned Aerial Systems) platforms, examples of which are listed in Table 1 (corresponding to Table 4.1-1 of 3GPP TR 38.821, see also Section 4.1 of 3GPP TR 38.821, Overview of Non-Terrestrial Networks):

[0149]

[0150] Table 1: Types of NTN platforms

[0151] For LEO, MEO and HEO satellites, whose positions do not remain fixed relative to a given Earth point, the satellite beam corresponding to the cell or PCI (Physical Cell ID) or SSB (Synchronization Signal Block) beam of the NR wireless system can move over the Earth.

[0152] NTN solutions that provide cells that continuously move across the Earth (e.g., NTNs based in low-Earth orbit, medium-Earth orbit, or HEO) are referred to as Earth-mobile cell solutions. This continuous cell motion across the Earth is due to the fact that the satellite beams are fixed relative to the NTN platform. Therefore, the cell coverage area, which may correspond to several satellite beams or just one, slides across the Earth's surface as the NTN platform (e.g., a low-Earth orbit satellite) moves.

[0153] Information about a satellite's orbital trajectory is contained in ephemeris data (or "satellite ephemeris data"). This data can be represented in various ways, one of which is using orbital parameters such as the semi-major axis, eccentricity, inclination, right ascension of the ascending node, periapsis, mean anomaly at a reference time, and epoch. The first five parameters determine an orbital plane (orbital plane parameters), while the other two are used to determine a precise satellite position (satellite-level parameters). Examples of orbital plane parameters and satellite-level parameters are provided in 3GPP TR 38.821 V16.0.0, section 7.3.6.1, "Representation of Complete Ephemeris Data." Another option is to provide the satellite's position coordinates (x, y, z), velocity vector (vx, vy, vz), and reference time.

[0154]

[0155] Table 2: Elements of the ephemeris

[0156] In an NTN system, several satellites may share a common orbital plane. In this case, some ephemeris data can be provided for orbital planes rather than for individual satellites to reduce the amount of data. The ephemeris data for each orbital plane can be stored in the UE or its Subscriber Identity Module (SIM). However, for networks with many satellites, the size of the ephemeris data can be quite large. Therefore, rather than storing the ephemeris data, the ephemeris data can be at least partially (or even completely) transmitted from the gNB.

[0157] For example, the satellite-level orbital parameters of all satellites that can serve the UE can be stored in the UE or SIM, and the ephemeris data of each satellite is associated with a satellite ID or index. The satellite ID or index of the serving satellite can then be broadcast in the system information so that the UE can find the corresponding ephemeris data in the SIM or memory of the UE. Alternatively, the satellite-level orbital parameters of the serving satellite can be broadcast in the system information, and the UE will derive the position coordinates of the serving satellite. The ephemeris data of neighboring satellites can also be provided to the UE through system information or dedicated RRC signaling. In the case where the baseline orbital plane parameters are provided in the UE or SIM, it may be sufficient to broadcast the average anomaly at the reference time point, and the epoch needs to be broadcast to the UE, thereby reducing overhead.

[0158] NTN timing advance and epoch time

[0159] NTN scenarios are characterized by long propagation delays, and UEs should account for these delays in their timing advance when transmitting on the uplink. Timing advance (TA) is a delay used to control the timing of uplink transmissions for a single UE. This helps ensure that uplink transmissions from all UEs are synchronized when received by the base station (network node). In terrestrial systems, the timing advance to be applied at the UE is transmitted from the network node to the specific UE.

[0160] The NTN transmission chain is divided into two sections: between the gateway and the satellite (feeder link), and between the satellite and the UE (serving link). The delay on the feeder link is called the "common delay" because it is the same for any UE served by the same NTN entity (e.g., satellite S1) (see, for example, Figure 8 The latency on the serving link is called “UE-specific latency” because the latency can be different for different UEs since they may be in different locations.

[0161] To avoid exposing the physical location of the network node (gNB) to the UE, 3GPP RAN1 decided to signal the feeder link delay as a common timing advance (see 3GPP TR 38.821 version 1.1.0, section 6.3.4), especially in Figure 6 In the architecture shown.

[0162] Using the UE's known location and satellite ephemeris, the serving link TA can be obtained autonomously at the UE. The UE's own location is usually available to the UE, especially if it can be assumed that the UE has access to a positioning system, such as a global navigation satellite system (GNSS), such as the Global Positioning System (GPS). As described in some of the above examples, ephemeris data is available to the UE (stored in the SIM card and / or obtained from system information signaling, etc.).

[0163] However, in general, the present invention is not limited to fully autonomous determination of the serving link TA component. Instead, the acquisition of the serving link TA component can also be aided by transmitting UE-specific information to a particular UE. Common TA refers to the common component of propagation delay shared by all UEs within the coverage area of ​​the same satellite beam / cell, which can be broadcast by the network on a per-satellite beam / cell basis. The calculation of the common TA is performed by the network under the assumption that there is at least one reference point per satellite beam / cell.

[0164] In other words, in the exemplary scenario, the UE autonomously calculates the UE-specific delay, assuming it supports GNSS. The UE calculates the feeder link delay based on a polynomial of the common TA. The sum of these delays provides the UE with the timing advance suitable for UL transmissions.

[0165] However, it is found that the feeder link delay can be time-varying, especially for fast-moving LEO satellites. Therefore, a single value representing the common table may lead to large approximation errors or require very frequent SIB updates. To reflect time variations, the common TA can be represented (approximated) as, for example, a polynomial.

[0166] As a specific scenario example, in Rel.17 NTN, UE transmission timing is adjusted based on propagation delay. Figure 9 Satellite 910 moves at a speed of 7.6 km / s (indicated by movement arrow 920 ), for example, and provides multiple (here, three) cells 990 .

[0167] The delay of the serving link 940 (between the UE 950 and the satellite 910) is calculated using satellite ephemeris (i.e., information about the satellite's position) and UE GNSS position information. Satellite ephemeris is broadcast via system information, and specifically, via the System Information Block (SIB) carrying NTN information (sometimes referred to as NTN-SIB). System information is broadcast by satellites 910. This disclosure is not limited to any particular network configuration. In some communication systems that may still benefit from this disclosure, satellites may be controlled to broadcast system information via gNB 960.

[0168] Feeder link 930 delay (between satellite 910 and gNB 960) can be compensated by the network (e.g., by the gNB) or by UE 950 based on common TA parameters broadcast via the NTN-SIB. Common TA parameters include information about feeder link delay and its variations, e.g., due to LEO satellite (or other type of satellite) movement.

[0169] Common timing advance parameters and other NTN-related parameters are carried by system information, such as in a specific NTN-SIB. The carried parameters may include one or more (or all) of the following:

[0170] - Ephemeris;

[0171] - Public TA parameters;

[0172] - Validity duration of UL sync information;

[0173] - t-Service (timing information about when the serving cell will stop serving the area);

[0174] - Cell reference location;

[0175] - epoch time;

[0176] - K_mac;

[0177] - Cell-specific Koffset;

[0178] - Network indication to enable / disable TA reporting

[0179] - Polarization indication

[0180] As described above, the ephemeris may include satellite orbit parameters such as anomaly (e.g., mean anomaly M at epoch time in radians); eccentricity; inclination; longitude (of ascending node); periapsis; and semi-major axis. The ephemeris may include the coordinates of the satellite position state vector and the coordinates of the satellite velocity state vector.

[0181] Common TA parameters include, for example, TACommon, TACommonDrifr, TACommonDriftVariant, and TACommonDriftVariation. Specifically, TACommon is the common timing advance value controlled by the network and can include any timing offset deemed necessary by the network. A TACommon value of 0 is supported. The granularity of TACommon is 4.07 × 10^(-3) μs. TACommonDrift indicates the drift rate of the common TA. The granularity of TACommonDrift is 0.2 × 10^(-3) μs / s. taCommonDriftVariant indicates the variation in the drift rate of the common TA. The granularity of TACommonDriftVariant is 0.2 × 10^(-4) μs / s^2. Values ​​are given in units of the corresponding granularity.

[0182] t-Service indicates the time when the cell provided by the NTN quasi-terrestrial fixed system will stop providing services for the area currently covered by it. The cell reference position is the reference position of the cell provided by the NTN quasi-terrestrial fixed system.

[0183] The epoch time indicates the epoch time of the assistance information (i.e., serving satellite ephemeris and common TA parameters). When explicitly provided through the SIB or through dedicated signaling, the epoch time is the start time of the DL subframe, indicated by the SFN and subframe number signaled together with the assistance information. The reference point for the epoch time of the serving satellite ephemeris and common TA parameters is the uplink time synchronization reference point.

[0184] If downlink and uplink frame timing are misaligned at the gNB, K_mac may be a scheduling offset provided by the network. The UE may need to make assumptions about the downlink configuration indicated by the MAC-CE command in the PDSCH. When the network does not provide the UE with a K_mac value, the UE assumes K_mac = 0. For the reference subcarrier spacing value of K_mac in FR1 (frequency range 1 between 410 MHz and 7125 MHz), a value of 15 kHz is used. The unit of K_mac is the number of slots for a given subcarrier spacing.

[0185] CellSpecific_K_offset is a scheduling offset used for timing relationships that need to be modified for NTN. The unit of K_offset is the number of slots for a given subcarrier spacing of 15 kHz.

[0186] ntnPolarizationDL can be optionally included in the NTN-SIB (sometimes also referred to as SIB NTN, SIB-NTN, etc.). If present, this parameter indicates the polarization information for downlink transmissions on the serving link: right-hand circular polarization (RHCP), left-hand circular polarization (LHCP), and linear polarization. Correspondingly, ntnPolarizationUL (if present) indicates the polarization information for the uplink serving link. If not present and ntnPolarizationDL is present, the UE assumes that the UL and DL have the same polarization.

[0187] As mentioned above, epoch time is the reference time for ephemeris and common TA parameters (assistance information). In other words, ephemeris and common TA parameters are generated based on epoch time. The UE 950 calculates satellite 910 position and feeder link 930 delay based on the time indicated as the epoch time and the satellite position determined based on the ephemeris. In NTN, epoch time is typically determined based on the SFN (System Frame Number) and subframe number, in case it is signaled in the NTN-SIB. In other contexts, such as the Unix operating system, epoch time is the number of seconds since January 1, 1970, 00:00:00 UTC (also known as the Unix epoch). It is a continuous time with no wraparound.

[0188] Note that the epoch time does not have to be explicitly signaled in the NTN-SIB and can be determined implicitly, for example, from the system information window.

[0189] As for the general system information content (SIB for terrestrial networks), there is a validity period (duration) for assistance information, including ephemeris and common TA parameters, during which the estimated values ​​(i.e., satellite position and feeder link delay) have sufficient accuracy. The validity period is indicated as the validity duration (VD), for example, within the NTN-SIB. It represents the validity duration of the entire NTN-SIB content. The validity period can be longer than the SFN period 1110. For example, for LEO, a maximum validity duration of 240 seconds is currently envisioned (or even infinite for GEO).

[0190] For example, 3GPP TS 38.321 provides a Timing Advance Report MAC CE, where the Timing Advance field indicates the minimum integer number of time slots greater than or equal to the Timing Advance value, i.e., the UE reports the TA value as , where SD represents the slot duration and ceil() represents the ceiling function.

[0191] Round trip time

[0192] For UE location management, it may be desirable for the network to independently verify the location reported by the UE. This verification may be performed based on the round trip time (RTT) of the signal. For example, Figure 11 As shown, the gNB transmits a downlink signal (e.g., a downlink positioning reference signal (DL-PRS)) at time t0. The signal is received by the UE at time t1. For example, the UE responds by transmitting an uplink signal (e.g., an uplink sounding reference signal (UL-SRS)) at time t2. The gNB may receive the uplink signal at time t3.

[0193] exist Figure 11 In the example, the round trip time RTT is determined as

[0194] .

[0195] In a terrestrial setting with stationary gNB and UE, the UE position can be determined as

[0196] ,

[0197] where c0 corresponds to the speed of light, p gNB is a vector with three components indicating the location of the gNB, p UE is a three-component vector indicating the UE's location, and the operator ‖.‖ returns the Euclidean norm of its argument (i.e., the distance between the gNB and the UE). Since the UE location is a three-component vector, the RTT will be measured at least three times, which is called multi-RTT (multiple round trip time).

[0198] For example, in a terrestrial setting, the RTT may be measured using at least three different transmit and receive points (TRPs).

[0199] For UE location verification in NTN using multiple RTTs with a single satellite in view, RTT is repeatedly measured with satellites at different points in time. The Location Management Function (LMF), explained in the 5G NR functional split between NG-RAN and 5GC section above, can establish a set of equations that relate RTT to the UE's location. This set of equations is numerically solved for the UE's location in an iterative manner.

[0200] 3GPP TS 38.215 defines the UE and gNB Rx-Tx Time Difference (RTTD), which is reported to the LMF to determine RTT and UE location. The gNB time difference between receiving Rx and sending Tx is defined as T gNB-RX – T gNB-TX , where T gNB-RXis the transmission and reception point (TRP) reception timing of the uplink subframe i containing the SRS associated with the UE, which is defined by the first detected path in time, and T gNB-TX It is the TRP transmission timing of the downlink subframe j that is closest in time to the subframe i received from the UE.

[0201] The UE time difference between receiving Rx and sending Tx is defined as T UE-RX – T UE-TX , where T UE-RX is the timing of the downlink subframe i received by the UE from the transmission point (TP), which is defined by the first detected path in time, and T UE-TX is the UE transmit timing of uplink subframe j that is closest in time to subframe i received from the TP.

[0202] For small cells in terrestrial networks, the RTT can be shown to be the sum of the UE-RTTD and the gNB-RTTD (see clause 8.10.4 of 3GPP TS 38.305). For larger cells in NTNs, there are issues related to timing advance (TA). For example, for a LEO satellite at an altitude of 600 km (LEO-600), the one-way delay is at least 2 ms, and the RTT is at least 8 ms. This means that the TA will also be at least 8 ms, which is equivalent to the duration of eight subframes.

[0203] Figure 12 An exemplary timing is shown in FIG, which indicates that the gNB-RTTD is based on the TRP transmission timing T of the downlink subframe j 1210 that is closest in time to the subframe i 1240 received from the UE. gNB-TX For UE-RTID, the UE transmit timing T of uplink subframe j+41230 UE-TX Closest in time to the subframe i received from the TP 1220. Under the concept that the UL subframe is closest in time to the DL subframe, calculating the RTT as the sum of UE-RTTD and gNB-RTTD underestimates the RTT because multiple subframes ( Figure 12 SF j, j+1, j+2, and j+3 in the example in .

[0204] As mentioned above, TS 38.321 provides a timing advance reporting MAC CE. However, the reported TA value includes rounding. Due to the rounding up of the TA value, the network cannot directly use the reported TA value to determine the RTT.

[0205] 5G NR offers positioning methods based on, for example, multiple round-trip time (multi-RTT) measurements. This multi-RTT positioning method is robust to network time synchronization errors. For multi-RTT, the LMF initiates a procedure whereby multiple TRPs and UEs in the terrestrial network perform gNB Rx-Tx and UE Rx-Tx measurements, respectively.

[0206] Example

[0207] To facilitate the determination of the round trip time, a correction based on the timing advance information is obtained. Such RTT may be used, for example, for estimating the position of the UE and / or verifying the position of the UE.

[0208] Below, a UE, base station, and procedures that meet these requirements will be described for the new radio access technology envisioned for 5G mobile communication systems, but they may also be used in LTE mobile communication systems or other communication systems. Various implementations and variations will also be explained. The following disclosure is facilitated by (and may, for example, be based at least in part on) the discussions and findings described above.

[0209] In general, it should be noted that many assumptions have been made herein in order to explain the underlying principles of the present invention in a clear, concise, and understandable manner. However, these assumptions should be understood as examples made herein for illustrative purposes only and should not limit the scope of this disclosure. Those skilled in the art will appreciate that the principles of the following disclosure and the principles set forth in the claims can be applied in different scenarios and in ways not explicitly described herein.

[0210] In addition, some of the terms used below for processes, entities, layers, etc. are closely related to terms used in LTE / LTE-A systems or current 3GPP 5G standardization, even though the specific terms used in the context of new radio access technologies for the next 3GPP 5G communication system have not yet been fully decided or may eventually change. Therefore, the terms may be changed in the future without affecting the functionality of the embodiments. Therefore, those skilled in the art will appreciate that the embodiments and their scope of protection should not be limited to the specific terms used exemplarily herein due to a lack of updated or ultimately agreed-upon terms, but should be understood more broadly in terms of the functions and concepts that form the basis of the functions and principles of the present disclosure.

[0211] For example, a mobile station, mobile node, user terminal, user device, or user equipment (UE) is a physical entity (physical node) within a communication network. A node may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a set of predetermined functions to other functional entities of the same or another node or network. A node may have one or more interfaces that connect the node to a communication facility or medium through which the node can communicate. Similarly, a network entity may have logical interfaces that attach the functional entity to the communication facility or medium, and through which the network entity can communicate with other functional entities or communication nodes.

[0212] The term "base station" or "radio base station" refers to a physical entity within a communications network. Like a mobile station, a base station may have several functional entities. A functional entity is a software or hardware module that implements and / or provides a set of predetermined functions to other functional entities in the same or another node or network. The physical entity performs several control tasks for communications devices, including one or more of scheduling and configuration. Note that base station functionality and communications device functionality can also be integrated into a single device. For example, a mobile terminal can also perform base station functionality for other terminals. LTE uses the term eNB (or eNodeB), while 5G NR currently uses the term gNB.

[0213] The term "non-terrestrial network (NTN) entity" can be broadly understood as an entity of a non-terrestrial network, such as a spacecraft or aircraft as described above in the section on NTN. Hereinafter, a satellite will be used as just one example of such an NTN entity, but it should be clear that other examples of NTN entities are also included.

[0214] For the following embodiments, it is exemplarily assumed that data transmission occurs between the UE and a network node via an NTN entity (e.g., a satellite). The term network node refers to Figure 6 A base station (e.g. gNB) in a NodeB, or another entity with an interface to the Core Network (CN), e.g. Figure 7 The NTN gateway shown in the above. Figure 8 and Figure 9 The following examples illustrate scenarios related to this. To simplify the explanation, the gateway and gNB (forming a network node) are collocated, thus avoiding the potential physical and logical separation of the gateway and gNB (base station) in the subsequent explanation. Therefore, the following examples will be described as occurring between the UE, NTN entities, and gNB, without specifically mentioning that the gateway is located between the NTN entities and the gNB or integrated within the gNB.

[0215] Figure 10A generalized, simplified, and exemplary block diagram of a user equipment (UE) 110 (also referred to as a communication device) and a scheduling device 160 (herein illustratively assumed to be located in a base station, such as an eLTE eNB (also referred to as ng-eNB) or gNB in ​​5G NR) is shown. The UE 110 and the eNB / gNB 160 each communicate with each other over a (radio) physical channel using a transceiver. This communication is illustrated by arrow 150. Furthermore, an NTN entity may have the same or similar structure as the scheduling device, for example, including a transceiver and processing circuitry. Therefore, the UE 110 and gNB 160 are part of the communication system 100.

[0216] Devices 110 and 160 may each include a transceiver 120, 170 and processing circuitry 130, 180. Transceivers 120, 170 may further include and / or function as both a receiver and a transmitter. Processing circuitry 130, 180 may be one or more hardware components, such as one or more processors or any large-scale integrated circuit. An input / output point (or node) exists between the transceiver and the processing circuitry, through which the processing circuitry controls the transceiver during operation, i.e., controls the receiver and / or transmitter and exchanges receive / transmit data. Transceivers acting as both transmitters and receivers may include an RF (radio frequency) front end, comprising one or more antennas, amplifiers, RF modulators / demodulators, and the like. The processing circuitry may perform control tasks, such as controlling the transceiver to transmit user data and control data provided by the processing circuitry and / or receive user data and control data further processed by the processing circuitry. The processing circuitry may also be responsible for performing other processes, such as determinations, decisions, calculations, and measurements. The transmitter may be responsible for performing the transmission process and other related processes. The receiver may be responsible for performing the reception process and other related processes, such as monitoring a channel.

[0217] The following describes various implementations of the improved transmission procedure. In this connection, improved entities involved in the improved transmission procedure are proposed, such as an improved UE, an improved NTN entity, and an improved base station. Corresponding methods for the UE, NTN entity, and base station behavior are also provided.

[0218] According to an embodiment, a network device (such as NTN entity 160) is provided. The network device includes a transceiver (such as Figure 10 ) and circuits such as the transceiver 170 shown in FIG. Figure 10 processing circuit 180 in the embodiment of the present invention).

[0219] The circuitry derives a round-trip time (RTT) for use in estimating the location of a user equipment (UE). This location estimate can be used, for example, to verify the location reported by the UE. The RTT is derived based on the UE's Rx-Tx time difference, which is the difference between the receive (Rx) timing of a subframe boundary in a UE's downlink frame and the transmit (Tx) timing of a subframe boundary in the UE's uplink frame that is closest in time to the received subframe. Furthermore, the RTT is derived based on the gNB Rx-Tx time difference, which is the difference between the receive timing of a subframe boundary in a gNB's downlink frame and the transmit timing of a subframe boundary in a gNB's uplink frame that is closest in time to the received subframe. Furthermore, the RTT is obtained based on timing advance TA information for the UE, the TA information indicating a rounded value of the timing advance value, and further, the RTT is obtained based on correction of the timing advance TA information for the UE.

[0220] The location estimate can be obtained by the Location Management Function (LMF), which is described in the 5G NR functional split between NG-RAN and 5GC section above. The LMF is a network entity within the 5G Core Network (5GC) (TS 29.572). As an example, the network entity can be dedicated hardware or a virtualized process within a processing device that performs the functions of the LMF.

[0221] The network device that obtains the RTT may include the functionality of the LMF, or may provide the obtained RTT to the LMF, for example, for location estimation.

[0222] A transceiver may receive information about a non-terrestrial network from a network node. The transceiver may perform circuit-controlled reception. In other words, the circuit may control (instruct) the transceiver, including instructing the receiver to receive information. Examples of network nodes include NTN equipment (such as a satellite or aircraft), a gNB, or a UE. Specifically, the transceiver may receive information based on one or more of the following: UE Rx-Tx time difference, gNB Rx-Tx time difference, TA information, and corrections to the TA information.

[0223] As mentioned above, the rounded value of TA is provided in MAC-CE (see TS 38.321), which indicates the minimum integer number of time slots greater than or equal to the timing advance value, which is referred to as TA report in this article. In other words, in NTN, the TA report value of the UE is available at any time. For example, the TA report value is determined as

[0224] ,

[0225] Wherein TA represents the timing advance value, SD is the time slot duration, and ceil() represents a ceiling function that returns the smallest integer greater than or equal to its argument.

[0226] For example, RTT is determined based on the UE's Rx-Tx time difference, the gNB's Rx-Tx time difference, a TA report as TA information, and a correction of the TA information.

[0227] In an exemplary embodiment, the RTT can be determined according to the following formula:

[0228] ,

[0229] Among them, UE RTTD Indicates UE Rx-Tx time difference, gNB RTTD Indicates the gNB Rx-Tx time difference, TA report Indicates TA information, and represents the correction of TA information, where SD is the time slot duration, and ceil() represents the ceiling function.

[0230] exist Figure 13 and Figure 14 An exemplary implementation for the case where the slot duration is the same as the subframe duration is shown in FIG. Figure 13 The TA 1310 in is greater than the subframe or slot duration of SF j to SF j+3 in the UE uplink frame UE-Tx. Therefore, the (TA information) TA report 1311 is rounded up to the duration of five subframes or slots of SF j to SF j+4. Figure 13 In the example, UE Rx-Tx time difference UE RTTD Refers to the subframe boundary, which is the subframe closest in time to the timing of the downlink subframe SF i received by the UE in the frame UE-Rx. Figure 13 UE Rx-Tx time difference UE RTTD is greater than zero because the closest subframe boundary in time is the boundary between subframes SF j+3 and SF j+4. Therefore, the available TA report can be corrected by one subframe or one or more time slots to obtain an accurate RTT.

[0231] exist Figure 13 In the example, RTT is obtained as , where the timing advance 1310 is calculated by using the TA report 1311 and the UE Rx-Tx time difference UE RTTD The RTT is obtained by using the readily available value of 1320 and the appropriate correction of one subframe in this example. The RTT is obtained as the obtained TA 1310 and the gNB Rx-Tx time difference gNB RTTD The sum of 1330.

[0232] exist Figure 14 In this example, TA 1410 is greater than the subframe or time slot duration of SF j to SF j+2 in the UE uplink frame UE-Tx, which results in rounding up and, therefore, a TA report value corresponding to the duration of time slots SF j to SF j+3 in the UE uplink frame UE-Tx. In this example, since the subframe boundary is closest in time to the boundary between subframes SF j+3 and SF j+4, the UE Rx-Tx time difference UE RTTD 1420 is less than zero. Therefore, in this example, the correction value is zero, and the RTT is obtained as , where the timing advance 1410 is obtained by using the TA report 1411 and the UE Rx-Tx time difference UE RTTD The RTT is obtained by using the readily available value of 1420 and appropriate corrections. The RTT is obtained as the obtained TA 1410 and the gNB Rx-Tx time difference gNB RTTD The sum of 1430.

[0233] For timeslot durations that are the same as subframe durations Figure 13 and Figure 14 In the example, the correction term Items in The absolute value of is less than 1, and therefore the rounding function returns zero slots or one slot as the appropriate correction. In other words, when the slot duration is the same as the subframe duration, the UE Rx-Tx time difference UE RTTD The value of the sign bit of indicates whether there is a correction of one time slot or zero time slots. RTTD < 0, the sign bit is equal to 1, and its reciprocal is equal to the correction term For UE RTTD > 0, the sign bit is equal to 0, and its reciprocal is equal to the correction term .

[0234] In general, the correction is not limited to the case when the slot duration is the same as the subframe duration.

[0235] A slot is part of the 5G NR frame structure, which consists of frames, subframes, and slots. Frames and subframes have durations of 10ms and 1ms, respectively. A slot is defined as a set of 14 consecutive OFDM symbols. The slot duration follows the subcarrier spacing of the network-configured bandwidth portion. A bandwidth portion can be configured for a single UE or multiple UEs. Depending on the subcarrier spacing of the 14 OFDM symbols, the slot duration can be 1ms, 0.5ms, 0.25ms, 0.125ms, and 0.06125ms.

[0236] The RTT may also be obtained based on the feeder link delay on the downlink and / or the feeder link delay on the uplink. Figures 6 to 8 Feeder links are discussed in detail. In other words, the determination of RTT may include feeder link delay on the downlink and / or feeder link delay on the uplink.

[0237] Figure 15 The feeder link delay on the downlink is shown in Figure 1. The gNB sends DL-PRS to the UE via an NTN entity (e.g., satellite). For example, the gNB sends DL-PRS at time t0, which is received by the satellite at time t1. Duration Corresponding to the feeder link delay in the downlink. The DL-PRS is received at the UE at time t2.

[0238] Figure 16 Figure 2 illustrates an example of feeder link latency on the uplink. Example scheduled SRS reception is performed. The gNB configures the UE's SRS signal via SRS resources, which can be grouped into SRS resource sets. Periodic SRS resource sets are configured via RRC signaling. Semi-persistent SRS resource sets are controlled via MAC CE for added flexibility. The gNB sends SRS-config at time t'0, which is received by the UE at time t'2. The UE responds by transmitting a UL-SRS at time t'4. Time t'4 is selected to satisfy the RRC-scheduled timeslot for reception at t'3 at the gNB. The duration τ3 between the satellite's UL-SRS transmission and its reception at the gNB corresponds to the feeder link latency on the uplink.

[0239] To improve the estimate of the UE's position, the RTT measurement may include corrections for the feeder link delay τ0 on the downlink and / or the feeder link delay τ3 on the uplink. Thus, the residual delay on the serving link may be defined as .

[0240] The network device may receive the downlink feeder link delay and the uplink feeder link delay from a UE, a gNB, or an NTN entity. Such an NTN entity may be, for example, a dedicated entity, such as an NTN control center. In other words, information regarding the downlink feeder link delay and the uplink feeder link delay may be available at the UE, gNB, and / or NTN entity. The information may be provided to the network device by any one of the UE, gNB, and NTN entity. Specifically, a transceiver included in the network device may receive information regarding the downlink feeder link delay τ0 and the uplink feeder link delay τ3 and may provide the information to the circuit.

[0241] For multi-RTT, the gNB and UE transmit, for example, a downlink positioning reference signal (DL-PRS) and an uplink sounding reference signal (UL-SRS). The gNB configures the UL-SRS for the UE using the RRC protocol. The LMF, however, provides the DL-PRS configuration to the UE using the LTE Positioning Protocol (LPP). In 4G, positioning support between the UE and the location server is handled by the LTE Positioning Protocol (LPP). This protocol has been extended to also support 5G positioning between the UE and the LMF.

[0242] The UE can use LPP to send measurement results to the LMF. The gNB can use NR Positioning Protocol A (NRPPa) to send measurement results to the LMF for UE position estimation. Due to the new next-generation interface between NG-RAN and the core network, the new NR Positioning Protocol A (NRPPa) protocol is introduced to carry positioning information between NG-RAN and LMF over the next-generation control plane interface (NG-C).

[0243] Based on the equation , various functional divisions between UE, gNB and LMF are feasible for calculating RTT.

[0244] For example, the UE may provide the network device with information about the UE RTTD TA report The UE may use LPP to report the measurement result to a network device, for example, to the LMF.

[0245] For example, the gNB can provide network equipment with information about the gNB RTTD TA report and feeder link delay. The gNB may use NRPPa to report measurements to network equipment, such as to the LMF for UE location verification.

[0246] Both NRPPa and LPP protocols can be sent on the control plane of the NG interface (NG-C) via the Access Mobility Function (AMF).

[0247] In a first exemplary embodiment, the network node receives a UE Rx-Tx time difference UE from the UE. RTTD and TA information TA report , and receives the gNB Rx-Tx time difference gNB from the gNB RTTD In particular, a transceiver included in a network node may receive the information. Furthermore, a circuit included in a network device may instruct the transceiver to receive the information.

[0248] This is Figure 17 and Figure 18As shown in FIG, the UE sends the TA report value to the LMF. Figure 17 and Figure 18 The LMF in the UE represents a network device including the LMF function. In addition, the UE Rx-Tx time difference UE RTTD The UE can send the data to the LMF using LPP. Figure 17 and 18 Indicated by the parallel marks on the arrows and the label LPP. For example, the list of information sent from the UE to the LMF can be extended to include a full TA report as defined in the Timing Advance Report MAC CE in TS 38.321.

[0249] In addition, gNB calculates the gNB Rx-Tx time difference gNB RTTD As mentioned above, the gNB can use NRPPa (which is in Figure 17 and Figure 18 The UE and gNB report their data to a network device (e.g., the LMF) using the parallel markings on the arrows (indicated by the parallel markings on the arrows and the label NRPPa). In other words, the UE and gNB send their data independently to the LMF, which performs all required processing. The RTT and / or multiple RTTs can be obtained (e.g., calculated) at the LMF.

[0250] exist Figure 17 In , the UE may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. Figure 18 In

[15] , the gNB may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink.

[0251] For example, TS 37.355 (17.3.0) already provides a field nr-NTA-Offset-r16 in NR-Multi-RTT-SignalMeasurementInformation, which can be modified to indicate the timing advance field as signaled in the timing advance report MAC CE element of TS 38.321. Such modification may include adding a new field as used in the timing advance report MAC CE.

[0252] In a second exemplary embodiment, supplementing the first exemplary embodiment, the gNB may further transmit scheduling information. In other words, the LMF or network equipment receives scheduling information from the gNB. This scheduling information may include K_offset, which is explained above in the "Timing Advance and Epoch Time for NTN" section. The value K_offset indicates the scheduling offset used for the timing relationship. Comparison of the K_offset with the TA report value can verify the TA report value. In other words, the gNB and / or network equipment including the LMF can verify the TA report value provided by the UE. Thus, tampering of the UE's TA report can be checked by comparing the UE's TA report with K_offset. Options for assessing a non-malicious UE are that the K_offset and TA report are within a window of N time slots, or that the K_offset is greater than or equal to the TA report.

[0253] Such an embodiment may increase the security of obtaining the RTT.

[0254] Figure 19 and Figure 20 Exemplarily indicates that except for gNB difference gNB RTTD Additional transmission of K_offset from gNB to LMF. In addition, similar to Figure 17 and Figure 18 For example, the UE reports the TA value UE difference UE RTTD Send to LMF.

[0255] exist Figure 19 In , the UE may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. Figure 20 In

[15] , the gNB may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink.

[0256] In a third exemplary embodiment, which complements the first exemplary embodiment, the transceiver also receives TA information from the gNB. In other words, the gNB can send the TA report value to the network device, and thus, for example, to the LMF. This embodiment enables cross-checking of the TA report sent by the UE to the network device. This cross-check can be performed by the gNB using the K_offset value available at the gNB.

[0257] Figure 25 and Figure 26This example illustrates the additional transmission of a TA report from the gNB to the LMF according to the third exemplary embodiment. For example, the UE sends the TA report to both the LMF and the gNB. In this exemplary embodiment, the gNB sends the TA report instead of the K_offset to the LMF. The LMF can check for tampering with both TA reports. Furthermore, the gNB can use the K_offset to verify the TA report. This embodiment can increase the security of RTT acquisition.

[0258] exist Figure 25 In , the UE may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. Figure 26 In

[15] , the gNB may optionally send a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink.

[0259] In a fourth exemplary embodiment, the network device may receive a corrected UE Rx-Tx time difference from the UE. RTTD,new The correction can be based on the UE RTT UE Rx-Tx time difference and TA information. For example, the corrected UE Rx-Tx time difference UE RTTD,new can be determined as

[0260] .

[0261] In other words, the corrected UE Rx-Tx time difference can be calculated as UE Rx-Tx time difference UE RTTD The UE may transmit the corrected UE Rx-Tx time difference via the LPP. The modification of the LPP may be performed similarly to that in the first exemplary embodiment.

[0262] In addition, the network device and therefore the LMF may receive the gNB Rx-Tx time difference from the gNB. The gNB may send the gNB Rx-Tx time difference via NRPPa.

[0263] exist Figure 21 and Figure 22 An example of signaling according to a fourth exemplary embodiment is given in . Figure 21 In the process, LMF receives the corrected UE Rx-Tx time difference UE sent via LPP from UE RTTD,new In addition, Figure 21 In the example, the gNB sends the gNBRx-Tx time difference.

[0264] exist Figure 21In the example of FIG. 1 , the feeder link delay τ0 on the downlink and the feeder link delay τ3 on the uplink may be additionally included in the corrected UE Rx-Tx time difference UE RTTD,new For example, the corrected UE Rx-Tx time difference UE RTTD,new can be determined as

[0265] .

[0266] In accordance with Figure 21 In the example of , the network device and, for example, its LMF may determine the RTT as

[0267] .

[0268] In other words, the residual RTT includes the sum of the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference.

[0269] Alternatively, optional values ​​for the feeder link delay τ0 on the downlink and the feeder link delay τ3 on the uplink may be provided by the gNB, similar to the values ​​for Figure 18 or 20 described examples.

[0270] exist Figure 22 In the process, LMF receives the corrected UE Rx-Tx time difference UE sent via LPP from UE RTTD,new In addition, Figure 22 In the example, the gNB may send a message including the corrected gNB Rx-Tx time difference, which is hereinafter referred to as the corrected gNB Rx-Tx time difference gNB RTTD,new The corrected gNB Rx-Tx time difference can be obtained as

[0271] .

[0272] In other words, the gNB Rx-Tx time difference gNB RTTD Subtract the feeder link delays τ0 and τ3 from the equation.

[0273] In accordance with Figure 22 In the example of , the network device and, for example, its LMF may determine the RTT as

[0274] .

[0275] In other words, the residual RTT includes the sum of the corrected UE Rx-Tx time difference and the corrected gNB Rx-Tx time difference.

[0276] Such signaling according to the fourth exemplary embodiment may reduce overhead by sending adapted (corrected) values ​​of the UE Rx-Tx time difference and / or the gNBRx-Tx time difference.

[0277] In a fifth exemplary embodiment, the network device receives the UE Rx-Tx time difference and the corrected TA information from the UE. For example, the UE transmits the UE Rx-Tx time difference and the corrected TA information to the network device. Furthermore, the network device in the fifth exemplary implementation receives the gNB Rx-Tx time difference from the gNB.

[0278] In particular, a transceiver included in the network node may receive the information sent by the UE and / or the gNB. Furthermore, circuitry included in the network device may instruct the transceiver to receive the information.

[0279] For example, the corrected TA information may be obtained based on the TA information and the correction of the TA information. The corrected TA information may be obtained as the sum of the TA information and the correction of the TA information.

[0280] .

[0281] Figure 23 A first example of the fifth exemplary embodiment is provided in For example, the UE sends the UE Rx-Tx time difference and the corrected TA information to the network device. The UE may send the correction of the UE Rx-Tx time difference and / or TA information via LPP.

[0282] Furthermore, the corrected TA information may include a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. In this case, the corrected TA information TA defined above may be adjusted by subtracting the feeder link delay values. report,new ,

[0283] .

[0284] In addition, the network device and therefore the LMF may receive the gNB Rx-Tx time difference from the gNB. The gNB may send the gNB Rx-Tx time difference via NRPPa.

[0285] In a first example of the fifth exemplary embodiment, RTT may be determined as the sum of the UE Rx-Tx time difference, the gNBRx-Tx time difference, and the corrected TA information,

[0286] .

[0287] In other words, the residual RTT according to the first example of the fifth exemplary embodiment includes the sum of the UE Rx-Tx time difference, the corrected gNB Rx-Tx time difference, and the corrected TA information.

[0288] Figure 24 A second example of the fifth exemplary embodiment is provided in

[0045] For example, the UE sends the UE Rx-Tx time difference and the corrected TA information to the network device. The UE may send the correction of the UE Rx-Tx time difference and / or TA information via LPP.

[0289] The corrected TA information according to the second example may be obtained as the sum of the TA information and the correction of the TA information,

[0290] .

[0291] Furthermore, the network device and therefore the LMF may receive a corrected gNB Rx-Tx time difference from the gNB. The gNB may send the gNB Rx-Tx time difference via NRPPa.

[0292] This corrected gNB Rx-Tx time difference can be obtained as

[0293] .

[0294] In other words, in the second example of the fifth exemplary embodiment, the feeder link delays τ0 and τ3 can be calculated from the gNBRx-Tx time difference gNB RTTD Subtract from .

[0295] In accordance with Figure 24 In the example of , the network device and, for example, its LMF may determine the RTT as

[0296] .

[0297] In other words, the residual RTT according to the second example of the fifth exemplary embodiment includes the sum of the UE Rx-Tx time difference, the corrected gNB Rx-Tx time difference, and the corrected TA information.

[0298] In a sixth exemplary embodiment, a network device may receive a UE Rx-Tx time difference, TA information, and a gNB Rx-Tx time difference from a gNB. Specifically, a transceiver included in the network node may receive the information transmitted by the gNB. Furthermore, circuitry included in the network device may instruct the transceiver to receive the information. The gNB may transmit the information including the UE Rx-Tx time difference, TA information, and gNB Rx-Tx time difference via NRPPa.

[0299] exist Figure 27 An example of signaling according to the sixth exemplary embodiment is given in . Figure 27 In the LMF, the LMF receives the UE Rx-Tx time difference, TA information, and gNB Rx-Tx time difference from the gNB. In addition, the gNB may optionally send the feeder link delay τ0 on the downlink and the feeder link delay τ3 on the uplink to the LMF. Figure 27 In the example of

[15] , the UE sends TA information (e.g., TA report) and UE Rx-Tx time difference to the gNB. The UE may use LPP to send TA information and UE Rx-Tx time difference to the gNB.

[0300] For example, the gNB can check for tampering of the TA report received from the UE, for example by using the K_offset value available at the gNB for scheduling. If the TA report provided by the UE is incorrect, communication with the UE may be impossible due to the mismatch between the UE TA and the K_offset. Therefore, the TA report sent from the gNB to the LMF may be more reliable than the TA report sent from the UE.

[0301] In a sixth exemplary embodiment, the network device may obtain the RTT as the sum of the UE Rx-Tx time difference, the gNB Rx-Tx time difference, and the corrected TA information, e.g.

[0302] .

[0303] In the case where the feeder link delay is taken into account, the network device may obtain the RTT by subtracting the feeder link delay from the RTT defined above.

[0304] .

[0305] In a seventh exemplary implementation, a network device may receive a RTT from a gNB. Specifically, a transceiver included in the network node may receive the RTT transmitted by the gNB. Furthermore, circuitry included in the network device may instruct the transceiver to receive the RTT. For example, the gNB may receive TA information and UE Rx-Tx time difference from the UE. The gNB may calculate the RTT based on the received information. In other words, the gNB preprocesses available and acquired information to determine (calculate) the RTT.

[0306] This is Figure 28As shown in Figure 1, the gNB receives TA information and the UE Rx-Tx time difference from the UE. The UE can send the TA information and the UE Rx-Tx time difference to the gNB using LPP. The gNB determines the RTT as the sum of the UE Rx-Tx time difference, the gNB Rx-Tx time difference, and the corrected TA information. Taking into account the feeder link delay, the network device can obtain the RTT by additionally subtracting the feeder link delays τ0 and τ3.

[0307] This embodiment can reduce signaling overhead and increase security because the gNB can verify the TA report similarly to the sixth exemplary embodiment.

[0308] In an eighth exemplary embodiment, a network device may receive corrected UE Rx-Tx time difference and gNBRx-Tx time difference from a gNB. Specifically, a transceiver included in the network node may receive the information transmitted by the gNB. Furthermore, circuitry included in the network device may instruct the transceiver to receive the information.

[0309] The corrected UE Rx-Tx time difference may be a correction based on the UE Rx-Tx time difference and the TA information. RTTD,new It can be UE Rx-Tx time difference UE RTTD , TA information TA report and the sum of the corrections to the TA information,

[0310] .

[0311] For example, where the feeder link delays τ0 and τ3 can be included in the corrected UE Rx-Tx time difference by subtraction, e.g.

[0312] .

[0313] exist Figure 29 Example signaling according to the eighth exemplary embodiment is provided in [ ]. Similar to the sixth and seventh exemplary embodiments, the UE transmits TA information and the UE Rx-Tx time difference to the gNB, for example, using LPP. The gNB may process the received information to obtain a corrected UE Rx-Tx time difference. The gNB may transmit the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference to the network device and, consequently, to the LMF.

[0314] The network device can then obtain the RTT by the sum of the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference, e.g.

[0315]

[0316] Similar to the sixth and seventh exemplary embodiments, the signaling according to the eighth exemplary embodiment can reduce signaling overhead and increase security. Similar to the sixth and seventh exemplary embodiments, the gNB can use the K_offset value to verify the TA report.

[0317] As already indicated above, an estimate of the UE's position can be obtained based on the RTT. The RTT can be obtained according to any of the above exemplary implementations. In general, an exemplary relationship between the RTT and the UE's position is given in the "Round Trip Time" section.

[0318] Obtaining an estimate of the UE's position may also include compensating for movement of non-terrestrial relays (eg, satellites) and / or movement of the Earth.

[0319] Since the UE position is a vector with three components, the RTT can be measured at least three times. For UE position estimation using multi-RTT with a single satellite in view in NTN, the RTT is repeatedly measured using the satellite at different points in time. For the three RTT measurements, the UE appears at six different locations in the equation system.

[0320] Therefore, the obtained RTT may be the first RTT, and the circuit included in the network device may also obtain the second RTT and the third RTT for estimating the position of the UE. In other words, the network device may obtain at least three RTTs at different times ti.

[0321] LMF can additionally compensate for the motion of the satellites and the Earth before solving for the UE position. This correction can be viewed as revolving the satellites and the Earth so that the UE position appears fixed. This correction can be performed by including the appropriate rotation matrix into the equations used for position determination.

[0322] For example, the relationship between RTT and the UE's position in the i-th measurement can be given as

[0323] ,

[0324] in and represents the rotation matrix, p sat refers to the position of the satellite at a specific time, p UE Corresponding to the position of UE at a specific time, c0 is the speed of light. i,1 , t i,2 、t' i,4 , and t' i,5 References Figure 16 The timing is shown, which is explained in detail above.

[0325] Furthermore, the network device (eg, circuitry included in the network device) may verify the UE's reported location based on an estimate of the UE's location, the estimate being based on the obtained RTT.

[0326] For example, a UE can use GNSS (Global Navigation Satellite System)-based location information to determine its position. However, network operators need to reliably know the location information of UEs attached to the network in order to select an appropriate core network. A malicious UE could spoof its selected PLMN (Public Land Mobile Network). Relying solely on GNSS-based location information reported by the UE is not considered reliable.

[0327] Therefore, the location can be verified based on the estimated location, which is based on the RTT. This verification can be performed independently of the UE's reported location information. If the reported UE location is consistent with the network-based assessment to within 5-10 km (i.e., similar to the size of a terrestrial macro cell), the UE location information can be considered verified, enabling country differentiation and selection of the appropriate core network to support all regulated services (i.e., emergency calls, lawful interception, public warnings, charging / billing).

[0328] Figure 30 A flowchart of an exemplary method to be performed at a network device is shown. Specifically, the network device may receive (S3010) information based on one or more of a UE Rx-Tx time difference, a gNB Rx-Tx time difference, TA information, and a correction of the TA information.

[0329] The RTT can be obtained based on the received information. A method for obtaining the round trip time of a non-terrestrial network by a network device is provided. Specifically, the RTT is obtained (S3020) for estimating the position of the UE. The RTT is obtained based on

[0330] - User Equipment UE Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of the UE and the transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to the subframe received by the UE,

[0331] - gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of the gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to the subframe received by the gNB,

[0332] - the UE's timing advance (TA) information, which indicates the rounded value of the timing advance value, and

[0333] - Correction of TA information.

[0334] The location of the UE may be estimated (S3030) as explained in detail above. Furthermore, the location of the UE may be verified (S3040) based on the estimated location, eg the location reported by the UE.

[0335] The present disclosure is not limited to network devices that include the functionality of LMF. Figures 17 to 29 The LMF functionality provided by the LMF block in the

[0015] may be included in a network device. For example, the network device obtains the RTT based on information provided by the UE and / or gNB and provides the RTT to the LMF, which may be hosted in another device.

[0336] The present disclosure can be implemented through software, hardware, or software in conjunction with hardware. Each functional block used in the description of each embodiment above can be partially or entirely implemented using an LSI (Large Scale Integration) such as an integrated circuit (IC), and each process described in each embodiment can be partially or entirely controlled by the same LSI or a combination of LSIs. An LSI can be implemented as a single chip, or a single chip can be formed to include some or all of the functional blocks. The LSI can also include data inputs and outputs coupled thereto. Depending on the level of integration, the LSI herein may be referred to as an IC, system LSI, super LSI, or ultra LSI. However, the technology used to implement an integrated circuit is not limited to LSI and can be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, an FPGA (Field Programmable Gate Array) that can be programmed after LSI fabrication or a reconfigurable processor that can reconfigure the connections and settings of the circuit cells arranged within the LSI can be used. The present disclosure can be implemented as either digital or analog processing. If future integrated circuit technology replaces LSI due to advances in semiconductor technology or other derivative technologies, the functional blocks can be integrated using future integrated circuit technology. Biotechnology can also be applied.

[0337] The present disclosure may be implemented by any kind of equipment, device, or system having a communication function, which is referred to as a communication device.

[0338] A communication device may include a transceiver and processing / control circuitry. The transceiver may include and / or function as both a receiver and a transmitter. As both a transmitter and a receiver, the transceiver may include an RF (radio frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, and other components.

[0339] Some non-limiting examples of such communication devices include phones (e.g., cellular (cell) phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, digital book readers, telehealth / telemedicine (remote health and medicine) devices, and vehicles providing communication capabilities (e.g., cars, airplanes, ships), and various combinations thereof.

[0340] Communication devices are not limited to portable or movable, and may also include any kind of device, equipment, or system that is non-portable or fixed, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines, and any other "things" in the network of the "Internet of Things (IoT)."

[0341] Communications may include exchanging data via, for example, cellular systems, wireless LAN systems, satellite systems, etc., and various combinations thereof.

[0342] The communication apparatus may include a device such as a controller or a sensor that is coupled to a communication device that performs the communication functions described in the present disclosure. For example, the communication apparatus may include a controller or a sensor that generates a control signal or a data signal used by the communication device that performs the communication functions of the communication apparatus.

[0343] Communications devices may also include infrastructure such as base stations, access points, and any other devices, equipment, or systems that communicate with or control devices such as those in the above non-limiting examples. Summary of the Invention

[0344] Corresponding to the above-mentioned network node and related further examples and implementations, the present disclosure provides a corresponding method performed by the network node or a processing circuit thereof.

[0345] A network device is provided, comprising: a transceiver and circuitry for obtaining an estimated round trip time (RTT) for a location of a user equipment (UE), wherein the RTT is obtained based on (i) a user equipment (UE) Rx-Tx time difference, which is a difference between a reception timing of a subframe boundary in a downlink frame of the UE and a transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to a subframe received by the UE, (ii) a gNB (gNB) Rx-Tx time difference, which is a difference between a reception timing of a subframe boundary in a downlink frame of the gNB and a transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to a subframe received by the gNB, (iii) timing advance (TA) information of the UE, the TA information indicating a rounded value of a timing advance value, and (iv) a correction of the timing advance (TA) information.

[0346] For example, the circuitry also obtains an estimate of the UE's location based on the obtained RTT.

[0347] For example, obtaining an estimate of the UE's position also includes compensating for movement of non-terrestrial relays and / or movement of the Earth.

[0348] As an exemplary embodiment, the obtained RTT is a first RTT, and the circuit further obtains a second RTT and a third RTT for estimation of the UE's position.

[0349] In some embodiments, the circuitry further verifies the UE's reported location based on an estimate of the UE's location, the estimate of the UE's location being based on the obtained RTT.

[0350] For example, RTT is determined according to the following formula

[0351] ,

[0352] Among them, UE RTTD Indicates UE Rx-Tx time difference, gNB RTTD Indicates the gNB Rx-Tx time difference, TA report Indicates TA information, and represents correction of TA information, where SD is the time slot duration, and ceil() represents a ceiling function that returns the smallest integer greater than or equal to its argument.

[0353] In some implementations, the RTT is also derived based on a feeder link delay on the downlink and / or a feeder link delay on the uplink.

[0354] As an exemplary embodiment, the transceiver receives a feeder link delay on a downlink and a feeder link delay on an uplink from a UE, a gNB, or an NTN entity.

[0355] For example, the transceiver also receives a UE Rx-Tx time difference from the UE, receives TA information from the UE, and receives a gNB Rx-Tx time difference from the gNB.

[0356] For example, the transceiver also receives scheduling information from the gNB.

[0357] For example, the transceiver also receives TA information from the gNB.

[0358] In some embodiments, the transceiver further receives a corrected UE Rx-Tx time difference from the UE, the corrected UE Rx-Tx time difference being based on the UE Rx-Tx time difference, the TA information, and the correction of the TA information, and receives a gNB Rx-Tx time difference from the gNB.

[0359] For example, the transceiver also receives the UE Rx-Tx time difference and the corrected TA information from the UE, and receives the gNB Rx-Tx difference from the gNB.

[0360] For example, the transceiver also receives UE Rx-Tx time difference, TA information, and gNB Rx-Tx time difference from the gNB.

[0361] As an exemplary embodiment, the transceiver further receives an RTT based on the UE Rx-Tx time difference, the gNB Rx-Tx time difference, the TA information, and the correction of the TA information from the gNB.

[0362] For example, the transceiver also receives a corrected UE Rx-Tx time difference from the gNB, which is based on the UE Rx-Tx time difference, the TA information and the correction of the TA information, and the gNB Rx-Tx time difference.

[0363] A method for obtaining a round trip time (RTT) by a network device of a non-terrestrial network is provided, the method comprising obtaining an estimated round trip time (RTT) for a location of a user equipment (UE), wherein the RTT is obtained based on (i) a user equipment (UE) Rx-Tx time difference, the time difference being a difference between a reception timing of a subframe boundary in a downlink frame of the UE and a transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to a subframe received by the UE, (ii) a gNB Rx-Tx time difference, the time difference being a difference between a reception timing of a subframe boundary in a downlink frame of the gNB and a transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to a subframe received by the gNB, (iii) timing advance (TA) information of the UE, the TA information indicating a rounded value of a timing advance value, and (iv) a correction of the timing advance (TA) information.

[0364] Note that the method may also be performed on a processing circuit of a network device or by an integrated circuit. In this case, instead of the receiving and converting steps, the method includes providing data for (wireless) transmission to a transceiver (or only to an output), and obtaining data (e.g., information on which the RTT is based) from a transceiver (or only at an input).

[0365] In the present disclosure, an integrated circuit (IC) is provided that performs a process of obtaining an estimated round-trip time (RTT) for a location of a user equipment (UE), wherein the RTT is obtained based on (i) a UE Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of the UE and the transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to the subframe received by the UE; (ii) a gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of the gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, the TA information indicating a rounded value of the timing advance value; and (iv) a correction to the timing advance (TA) information. The IC also includes an input to which system information is provided from a receiver. In a practical embodiment, this input may be connectable to or connected to a transceiver, which then performs reception of the information.

[0366] The present disclosure also provides program code, which, when executed on one or more processors, causes the one or more processors to perform any of the above methods. The program code may be stored on a non-transitory medium.

[0367] The present disclosure provides a communication system, which includes the network device described above, one or more user equipments, and one or more gNBs. The system may also include one or more NTN entities.

Claims

1. A network device for a non-terrestrial network, comprising: transceivers, and Circuit, the circuit: obtaining an estimated round trip time RTT for the location of the user equipment UE, The RTT is obtained based on - User Equipment (UE) Rx-Tx time difference, the UE Rx-Tx time difference being the difference between the reception timing of a subframe boundary in a downlink frame of the UE and the transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to the subframe received by the UE, - gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to the subframe received by the gNB, - Timing Advance (TA) information of the UE, the TA information indicating a rounded value of the Timing Advance value, and - Correction of the TA information.

2. The network device of claim 1 , wherein the circuit further obtains an estimate of the location of the UE based on the obtained RTT.

3. The network device of claim 2, wherein said obtaining an estimate of the position of the UE further comprises compensating for movement of non-terrestrial repeaters and / or movement of the earth.

4. The network device according to any one of claims 2 or 3, wherein the obtained RTT is a first RTT, and the circuit further obtains a second RTT and a third RTT for the estimate of the location of the UE.

5. The network device of any one of claims 2 to 4, wherein the circuit further verifies the reported location of the UE based on an estimate of the location of the UE, the estimate of the location of the UE being based on the obtained RTT.

6. The network device according to any one of claims 1 to 5, wherein the RTT is determined according to the following formula: ， Among them, UE RTTD Indicates the UE Rx-Tx time difference, gNB RTTD Indicates the gNB Rx-Tx time difference, TA report Indicates the TA information and represents the correction of the TA information, where SD is the time slot duration, and ceil() represents a ceiling function that returns the smallest integer greater than or equal to its argument. 7 . The network device according to claim 1 , wherein the RTT is obtained further based on a feeder link delay on a downlink and / or a feeder link delay on an uplink.

8. The network device according to claim 7, wherein the transceiver receives the feeder link delay on the downlink and the feeder link delay on the uplink from the UE, the gNB, or an NTN entity.

9. The network device according to any one of claims 1 to 8, wherein the transceiver further receiving the UE Rx-Tx time difference from the UE, receiving the TA information from the UE, and The gNB Rx-Tx time difference is received from the gNB.

10. The network device of claim 9, wherein the transceiver further receives scheduling information from the gNB.

11. The network device of claim 9, wherein the transceiver further receives the TA information from the gNB.

12. The network device according to any one of claims 1 to 8, wherein the transceiver further receiving a corrected UE Rx-Tx time difference from the UE, the corrected UE Rx-Tx time difference being based on the UE Rx-Tx time difference, the TA information, and a correction of the TA information, The gNB Rx-Tx time difference is received from the gNB.

13. The network device according to any one of claims 1 to 7, wherein the transceiver further receiving the UE Rx-Tx time difference and corrected TA information from the UE; Receive the gNB Rx-Tx difference from the gNB.

14. The network device according to any one of claims 1 to 8, wherein the transceiver further Received from the gNB - the UE Rx-Tx time difference, - the TA information, and - The gNB Rx-Tx time difference.

15. The network device according to any one of claims 1 to 7, wherein the transceiver further The RTT is received from the gNB, where the RTT is based on the UE Rx-Tx time difference, the gNB Rx-Tx time difference, the TA information, and a correction of the TA information.

16. The network device according to any one of claims 1 to 7, wherein the transceiver further Received from the gNB - a corrected UE Rx-Tx time difference, the corrected UE Rx-Tx time difference being based on the UE Rx-Tx time difference, the TA information and a correction of the TA information, and - The gNB Rx-Tx time difference.

17. A method for obtaining, by a network device, a round trip time of a non-terrestrial network, the method comprising: obtaining an estimated round trip time RTT for the location of the user equipment UE, The RTT is obtained based on - User Equipment (UE) Rx-Tx time difference, the UE Rx-Tx time difference being the difference between the reception timing of a subframe boundary in a downlink frame of the UE and the transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to the subframe received by the UE, - gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to the subframe received by the gNB, - Timing Advance (TA) information of the UE, the TA information indicating a rounded value of the Timing Advance value, and - Correction of the TA information.

18. An integrated circuit IC, wherein the integrated circuit IC obtaining an estimated round trip time RTT for the location of the user equipment UE, The RTT is obtained based on - User Equipment (UE) Rx-Tx time difference, the UE Rx-Tx time difference being the difference between the reception timing of a subframe boundary in a downlink frame of the UE and the transmission timing of a subframe boundary in an uplink frame of the UE, the transmission timing being closest in time to the subframe received by the UE, - gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in a downlink frame of a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB, the transmission timing being closest in time to the subframe received by the gNB, - Timing Advance (TA) information of the UE, the TA information indicating a rounded value of the Timing Advance value, and - Correction of the TA information.

19. Program code which, when executed on one or more processors, causes the one or more processors to perform the method according to claim 17.

20. A communication system, comprising The network device according to any one of claims 1 to 16, one or more user devices, and One or more gNBs.

Images