RTT determination for network-validated UE locations

Abstract

This disclosure relates to a network device for a non-terrestrial network and methods for such a network device. More specifically, the network device comprises a transmitting / receiving unit and a circuit for acquiring round trip time (RTT) for estimating the location of user equipment (UE), wherein the acquisition of the RTT is 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 that is temporally closest 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 a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB that is temporally closest to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, which indicates a rounded value of the timing advance value; and (iv) a correction value of the TA information.

Description

Technical Field

[0001] The present invention relates to the transmission of system information related to a non-terrestrial network. In particular, the present invention relates to apparatuses and methods for generating, signaling, receiving, and / or utilizing system information related to a non-terrestrial network.

Background Art

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

[0003] One objective is to provide a single technical framework that addresses all usage scenarios, requirements, and deployment scenarios, including at least enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communication (mMTC) (see, for example, Section 6 of Non-Patent Document 1). For example, eMBB deployment scenarios may include indoor hotspots, dense urban areas, suburbs, urban macro, and high-speed environments. URLLC deployment scenarios may include industrial control systems, mobile healthcare (remote monitoring, remote diagnosis, and remote treatment), real-time vehicle control, and wide-area monitoring and control systems for smart grids. mMTC deployment scenarios may include scenarios that use a large number of devices with little impact on data transmission latency, such as smart wearable terminals and sensor networks. eMBB and URLLC services are similar in that both require a very wide bandwidth, but URLLC services may preferably require ultra-low latency.

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

[0005] One of the notable features of 5G is the introduction of a non-terrestrial network (NTN), including satellites, in the communication path between user equipment and the network. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] 3GPP TR 38.913 v16.0.0 [Non-Patent Document 2] 3GPP TS 38.300 v16.3.0 [Non-Patent Document 3] ITU-R M.20183 [Non-Patent Document 4] 3GPP TS 38.211 v16.3.0 [Non-Patent Document 5] 3GPP TS 23.501 v16.6.0 [Non-Patent Document 6] 3GPP TR 38.811 v15.4.0 [Non-Patent Document 7] 3GPP TR 38.821 [Non-Patent Document 8] 3GPP TR 38.321 [Non-Patent Document 9] 3GPP TS 38.401 v16.1.0 [Non-Patent Document 10] 3GPP TS 38.215 [Non-Patent Document 11] 3GPP TS 38.305 [Non-Patent Document 12] 3GPP TS 29.572 [Non-Patent Document 13] 3GPP TS 37.355 v17.3.0 [Overview of the Initiative]

[0007] Non-limiting and exemplary embodiments facilitate the efficient transmission and reception of system information relating to non-terrestrial networks.

[0008] In exemplary embodiments, the technology disclosed herein features a network device comprising a transceiver unit and a circuit for acquiring round trip time (RTT) for estimating the location of user equipment (UE), wherein the acquisition of RTT is 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 that is temporally closest 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 a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB that is temporally closest to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, which indicates a rounded value of the timing advance value; and (iv) a correction value of the TA information.

[0009] It should be noted that general or specific embodiments may be implemented as systems, methods, integrated circuits, computer programs, storage media, or any selective combination thereof.

[0010] Further benefits and advantages of the disclosed embodiments and various implementations will become apparent from this specification and the drawings. These benefits and / or effects are provided by various embodiments and features of this specification and the drawings, respectively, but it is not necessary to provide all embodiments and features in order to obtain one or more of such benefits and / or effects. [Brief explanation of the drawing]

[0011] The following embodiments will be described in more detail with reference to the attached drawings. [Figure 1] Diagram showing a schematic architecture of the 3GPP NR system. [Figure 2] Schematic diagram showing the functional separation between NG-RAN and 5GC. [Figure 3] Sequence diagram of RRC connection setup / reconfiguration procedure [Figure 4] This schematic diagram illustrates usage scenarios for high-capacity, high-speed communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive Machine Type Communications), and highly reliable, ultra-low-latency communications (URLLC: Ultra Reliable and Low Latency Communications). [Figure 5] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario. [Figure 6] Diagram showing an exemplary NG RAN architecture based on transparent satellites. [Figure 7] Diagram showing an exemplary NG RAN architecture based on a regenerative satellite. [Figure 8] A diagram illustrating an exemplary scenario in which several UEs are served by satellites. [Figure 9] Diagram showing an exemplary NTN setup using a satellite moving at a constant speed. [Figure 10] Block diagram showing an exemplary structure of user equipment and network equipment. [Figure 11] Diagram showing the transmission and reception timings for DL-PRS and UL-SRS. [Figure 12] Schematic diagram showing the timing of subframes transmitted and received by the gNB or UE. [Figure 13]A schematic diagram showing a first exemplary correction of RTT based on the timing of subframes transmitted and received by the gNB or UE. [Figure 14] A schematic diagram showing a second exemplary correction of RTT based on the timing of subframes transmitted and received by the gNB or UE. [Figure 15] This diagram shows the timing of DL-PRS transmission from the gNB to the UE via satellite. [Figure 16] This diagram shows the timing of the SRS-config transmitted from the gNB to the UE via satellite and the UL-SRS transmitted from the UE to the gNB via satellite. [Figure 17] A schematic diagram illustrating a first example of a first exemplary embodiment in which the UE Rx-Tx difference and TA report are received from the UE, and the gNB Rx-Tx difference is received from the gNB. [Figure 18] A schematic diagram showing a second example of the first exemplary embodiment in which the UE Rx-Tx difference and TA report are received from the UE, and the gNB Rx-Tx difference is received from the gNB. [Figure 19] A schematic diagram illustrating the first example of a second exemplary embodiment in which the UE Rx-Tx difference and TA-report are received from the UE, and the gNB Rx-Tx difference and K_offset are received from the gNB. [Figure 20] A schematic diagram illustrating a second example of a second exemplary embodiment in which the UE Rx-Tx difference and TA report are received from the UE, and the gNB Rx-Tx difference and K_offset are received from the gNB. [Figure 21] A schematic diagram showing a first example of a fourth exemplary embodiment in which the corrected UE Rx-Tx difference is received from the UE and the gNB Rx-Tx difference is received from the gNB. [Figure 22] A schematic diagram showing a second example of a fourth exemplary embodiment in which the corrected UE Rx-Tx difference is received from the UE and the corrected gNB Rx-Tx difference is received from the gNB. [Figure 23] A schematic diagram showing a first example of a fifth exemplary embodiment in which the UE Rx-Tx difference and corrected TA information are received from the UE, and the gNB Rx-Tx difference is received from the gNB. [Figure 24] A schematic diagram showing a second example of a fifth exemplary embodiment in which the UE Rx-Tx difference and corrected TA information are received from the UE, and the corrected gNB Rx-Tx difference is received from the gNB. [Figure 25] A schematic diagram showing a first example of a third exemplary embodiment in which the UE receives the UE Rx-Tx difference and TA-report, and the gNB receives the gNB Rx-Tx difference and TA-report. [Figure 26] A schematic diagram showing a second example of a third exemplary embodiment in which the UE Rx-Tx difference and TA-report are received from the UE, and the gNB Rx-Tx difference and TA-report are received from the gNB. [Figure 27] A schematic diagram showing a sixth exemplary embodiment in which the UE Rx-Tx difference, TA report, and gNB Rx-Tx difference are received from the gNB. [Figure 28] 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. [Figure 29] A schematic diagram showing an eighth exemplary embodiment in which the corrected UE Rx-Tx difference and gNB Rx-Tx difference from the gNB are received. [Figure 30] A flowchart illustrating the steps to verify the UE's position based on position estimation derived from RTT measurements. [Modes for carrying out the invention]

[0012] <5G NR System Architecture and Protocol Stack> 3GPP is working towards the next release of fifth-generation cellular technology (also simply called "5G"), which includes the development of a new radio access technology (NR) that operates in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which will enable the prototyping and commercial deployment of smartphones compliant with the 5G NR standard.

[0013] In particular, the overall system architecture envisions an NG-RAN (Next Generation-Radio Access Network) with gNBs, which provide the UE-side termination for the NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are interconnected by Xn interfaces. Furthermore, the gNBs are connected to the NGC (Next Generation Core) by Next Generation (NG) interfaces, more specifically to the Access and Mobility Management Function (AMF, e.g., a specific core entity that performs AMF) by the NG-C interface, and to the User Plane Function (UPF, e.g., a specific core entity that performs UPF) by the NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, for example, Section 4 of Non-Patent Document 2).

[0014] The NR user plane protocol stack (see, for example, section 4.4.1 of Non-Patent Document 2) includes the PDCP (Packet Data Convergence Protocol; see section 6.4 of Non-Patent Document 2) sublayer, the RLC (Radio Link Control; see section 6.3 of Non-Patent Document 2) sublayer, and the MAC (Medium Access Control; see section 6.2 of Non-Patent Document 2) sublayer, which are terminated on the network side in the gNB. Furthermore, a new access layer (AS: Access Stratum) sublayer (SDAP: Service Data Adaptation Protocol) is introduced above the PDCP (see, for example, sub-clause 6.5 of Non-Patent Document 2). The NR also defines a control plane protocol stack (see, for example, section 4.4.2 of Non-Patent Document 2). An overview of the Layer 2 functions is described in sub-clause 6 of Non-Patent Document 2. The functions of the RRC layer are enumerated in sub-clause 7 of Non-Patent Document 2.

[0015] For example, the MAC layer is responsible for scheduling and scheduling-related functions, including logical channel multiplexing and processing of various numerologies.

[0016] The physical layer (PHY) is responsible for tasks such as coding, PHY HARQ processing, modulation, multi-antenna processing, and placing signals onto appropriate physical time-frequency resources. It also places transport channels onto 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 transmitting a particular transport channel, and each transport channel is placed on its corresponding physical channel. For example, the physical channels for uplinks are PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), and for downlinks are PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0017] Use cases / deployment scenarios for NR include eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable Low-Latency Communications), and mMTC (massive Machine Type Communication), which have diverse requirements regarding data rate, latency, and coverage. For example, eMBB requires support for peak data rates (20Gbps downlink, 10Gbps uplink) and effective (user-experienced) data rates approximately three times that of IMT-Advanced. On the other hand, URLLC has even stricter requirements, including ultra-low latency (user plane latency of 0.5ms for both UL and DL) and high reliability (1-10ms within 1ms). -5 ) and are imposed. In addition, mMTCs preferably have a high connectivity density (1 km in urban environments). 2The requirements may include 1,000,000 devices per unit, wide coverage in harsh environments, and ultra-long-life batteries (15 years) for low-cost devices.

[0018] Therefore, OFDM numerology suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not be effective for another use case. For example, low-latency services may preferably require shorter symbol lengths (and thus larger subcarrier spacings) and / or fewer symbols per scheduling interval (in other words, fewer TTIs) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require longer CP lengths than scenarios with short delay spreads. To maintain similar CP overhead, the subcarrier spacing needs to be optimized accordingly. NR may support multiple subcarrier spacing values. Therefore, subcarrier spacings of 15kHz, 30kHz, 60kHz, ... are currently being considered. Symbol length T u The subcarrier spacing Δf is given by the equation Δf = 1 / T u It is directly related by the following: Similar to the LTE system, the term "resource element" can be used to refer to the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0019] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each numerology and carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on its frequency index in the frequency domain and its symbol position in the time domain (see Section 4 of Non-Patent Literature 4). For example, downlink and uplink transmissions are organized into frames with a duration of 10 ms, and each frame consists of 10 subframes, each with a duration of 1 ms. In the 5G NR implementation, the number of consecutive OFDM symbols per subframe depends on the subcarrier interval setting. For example, with a 15 kHz subcarrier interval, a subframe has 14 OFDM symbols (similar to an LTE-compliant implementation, assuming a typical cyclic prefix). On the other hand, with a 30 kHz subcarrier interval, a subframe has two slots, each slot containing 14 OFDM symbols.

[0020] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 2 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0021] In particular, gNB and ng-eNB host the following main functions: - Radio resource management functions such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - Compression, encryption, and integrity protection of the IP header of the data; -Selection of the AMF when the UE attaches if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data for UPF; -Routing of control plane information to AMF; - Setting up and disconnecting connections; - Scheduling and sending paging messages; - Scheduling and transmission of system notification information (originating from AMF or Operation, Admission, Maintenance functions (OAM)); - Setting up measurements and reporting for mobility and scheduling; - Transport-level packet marking in uplink; -Session management; - Support for network slicing; - QoS flow management and mapping to data wireless bearers; - Support for UEs in the RRC_INACTIVE state; - Non-Access Stratum (NAS) message delivery function; - Sharing of wireless access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0022] The Access and Mobility Management Function (AMF) hosts the following main functions: - A function to terminate signaling in the non-accessible layer (NAS); - NAS signaling security; - Access Layer (AS) security control; - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of the UE in idle mode (including control and execution of paging retransmissions); - Management of the Registration Area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming permission checks; - Mobility management and control (enrollment and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0023] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor points for mobility within RATs / inter-RATs (where applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and enforcement of policy rules in the user plane; - Reporting traffic usage; - Uplink classifier that supports routing of traffic flow to data networks; - Branching point for supporting multi-homed PDU sessions; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Uplink traffic verification (mapping to SDF QoS flow); - Buffering downlink packets and triggering downlink data notifications.

[0024] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Policy enforcement and QoS of the control part; - Notification of downlink data.

[0025] Furthermore, the 5GC may include a Location Management Function (LMF) that includes the following functions: - Support for UE positioning; - Acquisition of downlink position measurement values or position estimation values from the UE; - Acquisition of uplink position measurement values from the NG RAN; - Acquisition of non-UE-related assistance data from the NG RAN; - Provision of notification assistance data to the UE and transfer of related encryption keys to the AMF.

[0026] <Procedures for setting up and reconfiguring the RRC connection> Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entity) when the UE transitions from RRC_IDLE to RRC_CONNECTED in the NAS part (see Non-Patent Document 2).

[0027] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. Specifically, this transition involves the AMF preparing UE context data (which includes, for example, PDU session context, security key, UE radio capability, UE security capability, etc.) and sending it to the gNB along with an Initial Context Setup Request. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding to the gNB with a SecurityModeComplete message. Subsequently, the gNB sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures itself to set up the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, gNB notifies AMF that the setup procedure is complete with an Initial Context Setup Response.

[0028] This disclosure provides a fifth-generation core (5GC) entity (e.g., AMF, SMF, etc.) comprising a control circuit for establishing a Next Generation (NG) connection with a gNB, and a transmission unit that sends an initial context setup message to the gNB via the NG connection, resulting in the setup of a signaling radio bearer between the gNB and the user equipment (UE). In particular, the gNB transmits radio resource control (RRC) signaling, including an 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 setting.

[0029] <IMT Usage Scenarios from 2020 Onward> Figure 4 shows some of the use cases for 5G NR. The 3rd Generation Partnership Project NR (3GPP NR) is considering three use cases where IMT-2020 is expected to support a wide variety of services and applications. The first phase of specification development for high-speed, high-capacity (eMBB) has been completed. In addition to further expanding eMBB support, research into standardization for ultra-high reliability, low latency (URLLC) and massive simultaneous connections is currently underway and will continue in the future. Figure 4 shows examples of usage scenarios expected for IMT after 2020 (see, for example, Figure 2 in Non-Patent Document 3).

[0030] URLLC use cases have stringent performance requirements for throughput, latency, and availability, and are envisioned as one of the future vertical applications that will enable wireless control of industrial production and manufacturing processes, telemedicine surgery, smart grid power distribution automation, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set out in Non-Patent Document 1. For NR URLLC in Release 15, the main requirement is to target a user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). A typical URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size when the user plane latency is 1 ms.

[0031] From a physical layer perspective, reliability can be improved in many ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, and repeated transmission of PDCCH. However, this room for improvement may expand towards achieving ultra-high reliability as NR becomes more stable and developed (in terms of critical requirements for NR URLLC). Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0032] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configurable grant) uplinks, slot-level repeat transmissions on data channels, and preemption on downlinks. Preemption means that a transmission for which a resource has already been allocated is stopped, and that allocated resource is used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, transmissions that were already permitted are replaced by later transmissions. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (eMBB, etc.). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for the 1E-5 target BLER.

[0033] A key characteristic of mMTC (Major Machine Type Communications) use cases is the extremely large number of connected devices that typically transmit relatively small amounts of data that are less susceptible to latency. These devices require low cost and very long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth portion is one solution that saves power from the UE and extends battery life.

[0034] As mentioned above, the scope of reliability improvements in NR is expected to broaden. High or very high reliability is a critical requirement in all cases, and especially for URLLC and mMTC. Several mechanisms can be considered to improve reliability from both a radio and network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, repeated transmission of data channel / control channel, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvements regardless of the specific communication scenario.

[0035] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include high reliability (10 6 It offers reliability up to a certain level, high availability, packet size up to 256 bytes, and time synchronization down to a few microseconds (depending on the use case, the value can be set to 1 microsecond or a few microseconds depending on the frequency range and short latency of about 0.5 ms to 1 ms (especially 0.5 ms latency on the target user plane)).

[0036] Furthermore, for NR URLLC, there may be several technical extensions from the perspective of the physical layer. These technical extensions include the extension of the Physical Downlink Control Channel (PDCCH) related to compact DCI, the repeated transmission of PDCCH, and the increase in the monitoring of PDCCH. In addition, the extension of UCI (Uplink Control Information) is related to the extension of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. There may also be extensions of PUSCH related to mini-slot level hopping and extensions of retransmission / repeated transmission. The term "mini-slot" refers to a transmission time interval (TTI) that contains fewer symbols than a slot (a slot contains 14 symbols).

[0037] <QoS Control> The QoS (Quality of Service) model of 5G is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR (Guaranteed Bit Rate) QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity QoS classification in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) carried in an encapsulation header via the NG-U interface.

[0038] 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) in accordance with the PDU session, as shown above, for example, referring to Figure 3. Additional DRBs for the QoS flow of that PDU session can be configured later (when this is done is up to the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC associate UL packets and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0039] Figure 5 shows the non-roaming reference architecture for 5G NR (see, for example, Non-Patent Document 5, Section 4.2.3). Application functions (AFs), such as external application servers hosting 5G services as illustrated in Figure 4, interact with the 3GPP core network to provide services. Examples include accessing Network Exposure Functions (NEFs) to support applications that affect traffic routing, and interacting with policy frameworks for policy controls such as QoS control (see Policy Control Functions (PCFs)). Application functions that are considered trusted by the operator based on operator deployment can interact directly with the relevant network functions. Application functions that are not permitted direct access to network functions by the operator interact with the relevant network functions using an open framework to the outside via the NEF.

[0040] Figure 5 further illustrates the 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, e.g., operator services, internet access, or third-party services). All or part of the core network functions and application services may be deployed and operated in a cloud computing environment.

[0041] Accordingly, this disclosure provides an application server (e.g., AF in a 5G architecture) comprising: a transmitter that, in operation, transmits a request to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) that includes QoS requirements for at least one of the URLLC service, eMBB service, and mMTC service, in order to establish a PDU session including a radio bearer between a gNB and a UE in accordance with QoS requirements; and a control circuit that, in operation, performs the service using the established PDU session.

[0042] <Sending system information> System information is downlink broadcast information periodically transmitted by base stations (gNBs in 5G, generally network nodes). System information includes information necessary for the UE to establish a connection with the base station. In 5G, the UE reads system information for cell camping when powered on, and system information for cell selection and re-selection when in RRC_IDLE mode. System information provides all the details necessary to access the network, such as system frame number, system bandwidth, PLMN, and cell selection and re-selection thresholds.

[0043] System information is structured into Master Information Blocks (MIBs) and System Information Blocks (SIBs). The SIB contains various types of information. Relevant information in this disclosure may include information related to NTN transmissions, as described below. MIB information is transmitted (broadcast) via BCH and PBCH channels, while SIBs are transmitted via DL-SCH and PDSCH channels.

[0044] Generally, system information is transmitted either periodically (so that newly connected terminals can acquire it) or on demand. The periodic schedule for system information transmission can be set by the RRC. In particular, SIB1 (referenced by the MIB) carries scheduling information that specifies, for example, the system information window (the repetition period of the system information transmission pattern), several transmission parameters for receiving system information (e.g., physical layer parameters), and the mapping of SIBs (transmission patterns) within the system information window.

[0045] <Non-Terrestrial Network (NTN)> By expanding service coverage capabilities and reducing the vulnerability of spacecraft / aircraft to physical attacks and natural disasters, NTN can facilitate the deployment of NR services in unserviced areas not covered by terrestrial NR networks (e.g., isolated or remote areas, on aircraft or ships) and areas where services are unavailable (e.g., suburbs and rural areas). Furthermore, NTN can enhance the reliability of NR services by providing continuity of service to passengers on moving platforms or ensuring service availability regardless of location, particularly in critical communications.

[0046] This advantage applies to either standalone non-terrestrial networks or networks that integrate terrestrial and non-terrestrial networks, and may affect coverage, user bandwidth, system capacity, and service reliability or usability.

[0047] A non-terrestrial network refers to, for example, a network or segment of a network that uses RF resources onboard a satellite. NTN typically comprises the following system elements: an NTN terminal, which may refer to a 3GPP UE, or a terminal specific to the satellite system if the satellite does not directly serve the 3GPP UE; a service link, which refers to the radio link between user equipment and the space / air platform; an air platform carrying the payload; a gateway connecting the space / air platform to the core network; and a feeder link, which refers to the radio link between the gateway and the space / air platform.

[0048] 3GPP has considered and described the operation of NR-based radio on non-terrestrial networks (NTN) (see, for example, Non-Patent Document 6, Study on New Radio (NR) to support non-terrestrial networks, and Non-Patent Document 7, Solutions for NR to support non-terrestrial networks, version 16.0.0).

[0049] A non-terrestrial network (NTN) refers to a network or network segment that uses RF resources mounted on entities located in the air or space for transmission, such as:

[0050] · Spacecraft: Satellites (including Low Earth Orbiting (LEO), Medium Earth Orbiting (MEO), Geostationary Earth Orbiting (GEO), and Highly Elliptical Orbiting (HEO) satellites);

[0051] • Aircraft: High Altitude Platform (HAP), including Unmanned Aircraft Systems (UAS). HAPs include Lighter than Air UAS (LTA) and Heavier than Air UAS (HTA), all of which operate at altitudes of 8km to 50km and are in a near-stationary state.

[0052] For example, a UAS or satellite platform connects to the 5G network via one or more gateways linked to the data network. NTN may include the following system elements: an NTN-enabled terminal, a 3GPP UE, or a terminal specific to the satellite system if the satellite does not directly service the 3GPP UE; a service link referring to the radio link between user equipment and the space / air platform; an air platform carrying the payload; a gateway connecting the space / air platform to the core network; and a feeder link referring to the radio link between the gateway center and the space / air platform. The platform may implement either transparent or regenerative payload transmission having the following exemplary characteristics:

[0053] In a transparent payload, the platform acts as a repeater by filtering, transforming, and amplifying the wave signal, but the payload remains unchanged.

[0054] In a regenerative payload, the platform has some or all of the functions of a base station. In addition to radio frequency filtering, conversion, and amplification, the platform may perform demodulation / modulation, switching / routing, and coding / decoding.

[0055] Inter-satellite links (ISLs) can be used as an option to form a satellite constellation. An ISL is a transport link between satellites.

[0056] Figure 6 illustrates a non-terrestrial network scenario in which transmission between terminals (UEs) takes place via a remote radio unit including a satellite and an NTN gateway. The gNB is located at the gateway as a scheduling device. The satellite payload performs frequency conversion and radio frequency amplification in both the uplink and downlink directions. Thus, the satellite repeatedly performs NR radio interface from the feeder link (between the NTN gateway and the satellite) to the service link (between the satellite and the UEs), and vice versa. The satellite radio interface (SRI) on the feeder link is NR-Uu. In other words, the satellite does not terminate the NR-Uu. A satellite in this configuration is called a transparent satellite.

[0057] Figure 7 illustrates a non-terrestrial network scenario in which transmission between terminals (UEs) is performed via a satellite including a gNB as a scheduling device. Satellites in this configuration are called regenerative satellites. According to an exemplary implementation (see Section 5.2 of Non-Patent Document 8), the NG-RAN logic architecture described in Non-Patent Document 9 is used as the basis for the NTN scenario. The satellite payload performs regeneration of signals received from Earth. The NR-Uu radio interface is on the service link between the UE and the satellite. The satellite radio interface (SRI) is the feeder link between the NTN gateway and the satellite. The satellite radio interface (SRI) is the transport link between the NTN GW and the satellite.

[0058] Figure 8 shows an exemplary scenario in which three UEs (UE1, UE2, and UE3) are served by satellite S1. Satellite S1 communicates via feeder links with the gNB and NTN gateway, as well as via an interstellar link (ISL) with another nearby satellite S2.

[0059] There are various types of satellites that provide communications, including low-earth orbit (LEO) satellites and geosynchronous equatorial orbit (GEO) satellites (also called geostationary satellites). Geostationary satellites move at the same angular velocity as the Earth and orbit parallel to the Earth's rotation, so they appear stationary and thus provide coverage to a specific area. GEO satellites appear stationary from the ground. LEO satellites orbit at an altitude of 160 to 2000 kilometers (99 to 1200 miles). A constellation of LEO satellites can provide continuous coverage to the entire world as the satellites move. Also, unlike GEO satellites, LEO satellites fly at much faster speeds because they are closer to the Earth.

[0060] GEO satellites have many applications, including weather forecasting, satellite radio, and television. However, because GEO satellites orbit at very high altitudes, there is a long communication delay (latency) as signals travel between these satellites. Therefore, many critical communications are handled via the LEO satellite network, which enables high-speed connectivity without the need for wires or cables.

[0061] However, in general, NTN may have various types of platforms, including not only satellites but also UAS (Unmanned Aerial System) platforms. Examples of these are shown in Table 1 (corresponding to Table 4.1-1 of Non-Patent Literature 7; see also Non-Patent Literature 7, Section 4.1, Overview of Non-Terrestrial Networks).

[0062] [Table 1]

[0063] In LEO, MEO, and HEO satellites, whose position is not fixed relative to a given ground point, the satellite beam corresponding to the NR radio system cell, i.e., the Physical Cell ID (PCI) or Synchronization Signal Block (SSB) beam, can move across the Earth.

[0064] An NTN scenario that provides cells that move continuously across the Earth (e.g., LEO, MEO, or HEO-based NTN) is called a Earth-moving cell scenario. The cells move continuously across the Earth because the satellite beams are fixed to the NTN platform. Therefore, the footprint of several satellite beams or the cells corresponding to one satellite beam slides across the Earth's surface as the NTN platform (e.g., LEO satellite) moves.

[0065] Information regarding the trajectory of a satellite's orbit is contained in ephemeris data (or "satellite ephemeris data"). Ephemeris data can be represented in various ways, one of which is by using orbital parameters such as the semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, mean ephemeris at reference time, and epoch. The first five parameters can be used to determine the orbital plane (orbital plane parameters), and the other two parameters are used to determine the precise satellite position at a given time (satellite level parameters). Orbital plane parameters and satellite level parameters are exemplified in Non-Patent Document 7 V16.0.0, Section 7.3.6.1, "Representation of Complete Ephemeris Data". Another possible option is to provide the coordinates of the satellite position (x, y, z), the velocity vector (vx, vy, vz), and a reference point in time.

[0066] [Table 2]

[0067] In the NTN system, some satellites may share a common orbital plane. In such cases, in order to reduce the data volume, some ephemeris data may be provided for the orbital plane rather than for a single satellite. The ephemeris data for each orbital plane may be stored in the UE or the UE's SIM (Subscriber Identity Module). However, in a network containing many satellites, the size of the ephemeris data may instead become large. Therefore, rather than storing the ephemeris data, the ephemeris data may be transmitted from the gNB at least partially (or completely).

[0068] For example, satellite-level orbital parameters for all satellites that may provide services to the UE may be stored in the UE or SIM, and the ephemeris data of each satellite is linked to a satellite ID or index. Then, the satellite ID or index of the serving satellite is notified in the system information, and the UE may be able to discover the corresponding ephemeris data in the UE's SIM or storage. Alternatively, the satellite-level orbital parameters of the serving satellite may be notified in the system information, and the UE may be able to derive the position coordinates of the serving satellite. The ephemeris data of adjacent satellites may be provided to the UE via the system information or dedicated RRC signaling. When the reference orbital plane parameters are provided to the UE or SIM, it is sufficient to notify the mean argument of perigee and the epoch at the reference time to the UE, thereby reducing the overhead.

[0069] <Timing Advance and Epoch Time in NTN> The NTN scenario is characterized by long propagation delays, and UEs should consider these delays in their timing advance when transmitting on the uplink. Timing advance (TA) is a delay used to control the uplink transmission timing of individual UEs. This ensures that all uplink transmissions from UEs are synchronized when received by the base station (network node). In existing ground systems, the timing advance applied to a UE is transmitted from the network node to the specific UE.

[0070] NTN's transmission chain is divided into two segments: the feeder link between the gateway and the satellite, and the service link between the satellite and the UEs. The delay in the feeder link is the same for any UEs (e.g., UE1, UE2, and UE3 in Figure 8) being serviced by the same NTN entity (e.g., satellite S1), and is therefore called the "common delay." The delay in the service link can differ for each UE because the UEs may be located in different places, and is therefore called the "UE-specific delay."

[0071] To prevent the physical location of network nodes (gNBs) from being revealed to the UE, 3GPP RAN1 decided to signal feeder link delay as a common timing advance value, particularly in the architecture shown in Figure 6 (see Non-Patent Document 7, v.1.1.0, Section 6.3.4).

[0072] Autonomous acquisition of Service Link TA in a UE is possible using the UE's known position and satellite ephemeris. The UE's own position is typically available when the UE is available, and especially when it is assumed that the UE can access a positioning system such as a Global Navigation Satellite System (GNSS), such as the Global Positioning System (GPS). As mentioned in some of the examples above, ephemeris data can be made available to the UE (stored in the SIM and / or obtained from system information signaling, etc.).

[0073] However, in general, this disclosure is not limited to the fully autonomous determination of service link TA components. Rather, the acquisition of service link TA components can also be assisted by signaling UE-specific information to a particular UE. Common TA refers to a common component of propagation delay shared by all UEs within the coverage of the same satellite beam / cell, but which may be communicated by the network for each satellite beam / cell. This common TA is calculated by the network, assuming at least one reference point per satellite beam / cell.

[0074] In other words, in the exemplary scenario, the UE is assumed to be GNSS-enabled and therefore autonomously calculates its own delays. The UE calculates the feeder link delay based on a common TA polynomial. The sum of these delays provides the UE with a timing advance value applicable to UL transmission.

[0075] However, it has been found that feeder link delay can be time-varying, especially in high-speed moving LEO satellites. Therefore, representing the common TA with a single value may result in large approximation errors or require frequent SIB updates. To reflect time variations, the common TA can be expressed (approximated) as, for example, a polynomial.

[0076] As a specific scenario example, in Rel.17 NTN, UE transmission timing is adjusted based on propagation delay. This is shown in Figure 9. Satellite 910 is moving at a speed of, for example, 7.6 km / s (movement is indicated by the movement arrow 920). Satellite 910 provides multiple (three in this case) cells 990.

[0077] The delay of service link 940 (the delay between UE950 and satellite 910) is calculated using satellite ephemeris (i.e., information about the satellite's position) and UE's GNSS position information. Satellite ephemeris is broadcast via system information, in particular via a System Information Block (SIB) (sometimes called NTN-SIB) that carries NTN information. System information is broadcast by satellite 910. This disclosure is not limited to any particular network configuration. In some communication systems that benefit from this disclosure, the satellite may be controlled to broadcast system information by gNB960.

[0078] The delay in feeder link 930 (the delay between satellite 910 and gNB 960) may be compensated by the network (e.g., gNB) or by UE 950 based on common TA parameters broadcast via NTN-SIB. The common TA parameters include information about feeder link delay and its variations, for example, due to the movement of LEO satellites (or other types of satellites).

[0079] Common timing advance parameters and further NTN-related parameters are carried by system information, such as a specific NTN-SIB. The parameters carried may include one or more (or all) of the following:

[0080] - Ephemeris; - Common TA parameters; - Validity period of UL synchronization information; -t-Service(information about when a serving cell will stop providing service in an area); -Cell reference position; - Epoch time; -K_mac; -Cell-specific Koffset; - Instructions for TA reports indicating whether the network has been enabled / disabled; Polarization indication.

[0081] As described above, the ephemeris may include satellite orbit parameters such as the angle of periphery (e.g., mean angle of periphery M (in radians) at the epoch), eccentricity, inclination angle, longitude (longitude of the ascending node), periphery, and semi-major axis. The ephemeris may also include the coordinates of the satellite position state vector and the satellite velocity state vector.

[0082] Common TA parameters include, for example, TACommon, TACommonDrift, TACommonDriftVariant, and TACommonDriftVariation. In particular, TACommon is a common timing advance value for network control and may include any timing offset that the network deems necessary. A value of 0 for TACommon 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 / s². Values ​​are given in units of the corresponding granularity.

[0083] t-Service indicates time information regarding when a cell provided via the NTN quasi-global fixed system will cease service in the area it currently covers. The cell reference location is the reference location of the cell provided via the NTN quasi-global fixed system.

[0084] The epoch time indicates the epoch time of the support information (i.e., serving satellite ephemeris and common TA parameters). When explicitly provided via SIB or dedicated signaling, the epoch time is the start time of the DL subframe indicated by the SFN and subframe number signaled along with the support information. The reference point for the epoch time of the serving satellite ephemeris and common TA parameters is the uplink time synchronization reference point.

[0085] K_mac is a scheduling offset provided by the network when the downlink frame timing and uplink frame timing do not match in the gNB. K_mac may be required for the UE's operation and assumptions regarding downlink configuration, as indicated by the MAC-CE command in the PDSCH. If the UE is not provided with a K_mac value from the network, the UE assumes K_mac = 0. In FR1 (frequency range 1 from 410MHz to 7125MHz), a value of 15kHz is used as the reference subcarrier interval for the unit of K_mac. The unit of K_mac is the number of slots for a given subcarrier interval.

[0086] 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 interval of 15 kHz.

[0087] ntnPolarizationDL may be optionally included within NTN-SIB (sometimes called SIB NTN, SIB-NTN, etc.). If present, this parameter indicates polarization information for downlink transmissions in a service link, including right-hand circular polarization (RHCP), left-hand circular polarization (LHCP), and linear polarization. Similarly, if present, ntnPolarizationUL indicates polarization information for uplink service links. If ntnPolarizationUL is not present but ntnPolarizationDL is, the UE assumes the same polarization for both UL and DL.

[0088] As described above, the epoch time is the reference time for the ephemeris and common TA parameters (supporting information). In other words, the ephemeris and common TA parameters are generated based on the epoch time. The UE950 calculates the position of satellite 910 and the delay of feeder link 930 based on the time indicated as the epoch time and the satellite position determined based on the ephemeris. In NTN, the epoch time is usually represented by the SFN (System Frame Number) and subframe number when signaled in NTN-SIB. In other contexts, for example, in the Unix operating system, the epoch time is the number of seconds elapsed since January 1, 1970, 00:00:00 UTC (also known as the Unix epoch), and is a continuous time without wrap-around.

[0089] It should be noted that epoch time does not need to be explicitly signaled in NTN-SIB, and may be implicitly determined, for example, according to the system information window.

[0090] For standard system information content (SIB used in terrestrial networks), a validity period (duration) is set for supporting information, including ephemeris and common TA parameters, during which the estimates (i.e., satellite position and feeder link delay) have sufficient accuracy. The validity period is indicated, for example, as Validity Duration (VD) within NTN-SIB. This indicates the validity period of all content in NTN-SIB. The validity period may be longer than SFN cycle 1110. For example, for LEO, the maximum validity period is currently assumed to be 240 seconds (infinite for GEO).

[0091] For example, Non-Patent Document 8 defines a Timing Advance Report MAC CE that includes a Timing Advance field indicating the smallest integer slot greater than or equal to the Timing Advance value. That is, the UE reports the TA value as ceil(TA value / SD)*SD, where SD represents the slot length and ceil() represents the ceiling function.

[0092] <Round trip time> In UE location management, it is sometimes desirable for the network to independently verify the location reported by the UE. Such verification may be based on the round trip time (RTT) of the signal. For example, as shown in Figure 11, the gNB transmits a downlink signal, such as a Downlink Positioning Reference Signal (DL-PRS), at time t0. This signal is received by the UE at time t1. For example, the UE responds at time t2 by transmitting an uplink signal, such as an Uplink Sounding Reference Signal (UL-SRS). The uplink signal may be received by the gNB at time t3.

[0093] In the example shown in Figure 11, the round-trip time (RTT) is determined as follows.

number

Number

Number

[0094] For example, in the case of a terrestrial network, the RTT can be measured using at least three different transmission and reception points (TRP: transmission and reception point).

[0095] For UE position verification in NTN by multi RTT using a single satellite within the line of sight, the RTT is repeatedly measured using the satellite at different time points. The location management function (LMF) described in <Functional Separation between NG-RAN and 5GC in 5G NR> above may construct a system of equations that associates all of them with the RTT and the position of the UE. This system of equations is numerically solved iteratively for the position of the UE.

[0096] In Non-Patent Document 10, the Rx-Tx time difference (RTTD: Rx-Tx Time Difference) of the UE and gNB reported to the LMF to determine the RTT and the UE position is defined. The gNB time difference between reception Rx and transmission Tx is T gNB-RX - T gNB-TX is defined as, where TgNB-RX This is the reception timing of the transmission and reception point (TRP) of the uplink subframe i, which includes the SRS associated with the UE, defined by the first detected path in time. gNB-TX This is the TRP transmission timing of the downlink subframe j that is temporally closest to subframe i received from the UE.

[0097] The UE time difference between the received Rx and transmitted Tx is T UE-RX - T UE-TX Defined as, where T UE-RX This is the UE reception timing of the downlink subframe i from the transmission point (TP), defined by the path that was first detected in time, and T UE-TX This is the UE transmission timing of the uplink subframe j that is temporally closest to subframe i received from TP.

[0098] For small cells in terrestrial networks, RTT has been shown to be the sum of UE-RTTD and gNB-RTTD (see Section 8.10.4 of Non-Patent Document 11). For NTN's larger cells, there is a problem with timing advance (TA). For example, for the 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 is also at least 8 ms, which is equivalent to the length of eight subframes.

[0099] An example timing is shown in Figure 12, which shows the TRP transmission timing T of the downlink subframe j1210 that is temporally closest to subframe i1240 received from the UE by gNB-RTTD. gNB-TX This indicates that, for UE-RTTD, for subframe i1220 received from TP, the UE transmit timing T of uplink subframe j+4 1230 is indicated. UE-TXHowever, it is the closest in time. If we assume that the UL subframe is the closest in time to the DL subframe and calculate the RTT as the sum of UE-RTTD and gNB-RTTD, several subframes (SFj, j+1, j+2, and j+3 in the example in Figure 12) are implicitly ignored, so the RTT will be underestimated.

[0100] As mentioned above, Non-Patent Document 8 defines the Timing Advance Report MAC CE. However, the reported TA value includes rounding operations. By rounding up the TA value, the network cannot directly use the reported TA value to determine the RTT.

[0101] For example, 5G NR specifies a location determination method based on multiple round-trip time (multi-RTT) measurements. Such a multi-RTT location determination method is less susceptible to network time synchronization errors. In multi-RTT, the LMF initiates the procedure, which causes multiple TRPs and UEs in the terrestrial network to perform gNB Rx-Tx measurements and UE Rx-Tx measurements, respectively.

[0102] <Embodiment> To facilitate the determination of round-trip time, acquisition is performed based on correction of timing advance information. Such RTT can be applied, for example, in the estimation and / or verification of the UE's position.

[0103] The following describes new radio access technologies envisioned in 5G mobile communication systems, including UEs, base stations, and procedures to meet these needs, although these may also be used in LTE mobile communication systems or other communication systems. Various implementations and modifications are also described. The following disclosures are facilitated by the above discussions and findings, and can be based, for example, on at least some of them.

[0104] It should be noted that, in general, many assumptions are made herein in order to explain the underlying principles in a clear, concise, and understandable manner. However, these assumptions are merely illustrative and should not be understood as limiting the scope of this disclosure. Those skilled in the art will notice that the principles of the disclosure and the claims described herein can be applied to different scenarios and in ways not expressly described herein.

[0105] Furthermore, some of the terms used below, such as procedures, entities, and layers, are closely related to the terminology used in LTE / LTE-A systems or current 3GPP 5G standardization, but certain terms used in the context of new radio access technologies for the next 3GPP 5G communication systems are not yet fully determined or may ultimately change. Thus, terminology may change in the future without affecting the functionality of the embodiments. As a result, those skilled in the art will recognize that embodiments and their scope of protection should not be limited to specific terms used exemplary in this specification in the absence of newer or ultimately agreed-upon terms, but should be understood more broadly by the functions and concepts underlying the functions and solutions of the disclosure.

[0106] For example, a mobile station or mobile node or a user terminal or user equipment or user device (UE) is a physical entity (physical node) in a communication network. A single node may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to the same or another node or other functional entities in the network. A node may have one or more interfaces that attach it to communication equipment or media that enable the node to communicate. Similarly, a network entity may have logical interfaces that attach functional entities to communication equipment or media that enable communication between itself and other functional entities or corresponding nodes.

[0107] In this specification, the terms “base station” or “radio base station” refer to a physical entity within a communication network. Similar to a mobile station, a base station may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to the same or another node or other functional entities in the network. A physical entity performs several control tasks relating to a communication device, including one or more of scheduling and configuration. The functions of a base station and a communication device may be integrated within a single device. For example, a mobile terminal may implement the functions of a base station for other terminals. The term used in LTE is eNB (or eNodeB), while the term currently used for 5G NR is gNB.

[0108] The term Non-Terrestrial Network (NTN) entity can be broadly understood as a non-terrestrial network entity such as a spacecraft or aircraft, as explained in the section related to NTN above. While only satellites are assumed as examples of such NTN entities below, it is clear that other examples of NTN entities are also covered.

[0109] In the following embodiments, it is assumed, illustratively, that data transmission takes place between the UE and a network node via an NTN entity (e.g., a satellite). The term "network node" refers to a base station (e.g., a gNB) as shown in Figure 6, or to another entity that has an interface to the core network (CN), such as an NTN gateway as shown in Figure 7. Scenarios already introduced in Figures 8 and 9 can be referenced illustratively. For the sake of simplicity, it is assumed that the gateway and the gNB (forming the network node) are collocated, thereby avoiding the possibility of the gateway and the gNB (base station) being physically and logically separated in the following description. Therefore, the embodiments are described below as occurring between the UE, the NTN entity, and the gNB, without specifically mentioning that the gateway is located between the NTN entity and the gNB, or integrated into the gNB.

[0110] Figure 10 shows a general, simplified, exemplary block diagram of user equipment 110 (also called a communication device) and scheduling device 160 (here located at a base station, e.g., an eLTE eNB (also called an ng-eNB) or a gNB in ​​5G NR). UE110 and eNB / gNB160 communicate with each other via a (radio) physical channel using transceivers. The communication is indicated by arrow 150. Furthermore, NTN entities may have the same or similar structure as the scheduling device, for example, including transceivers and processing circuits. Thus, UE110 and gNB160 are part of the communication system 100.

[0111] Both devices 110 and 160 may include transceiver units 120 and 170 and processing circuits 130 and 180. The transceiver units 120 and 170 include a receiver and a transmitter, and / or function as a receiver and a transmitter. The processing circuits 130 and 180 may be one or more hardware components such as one or more processors, or any LSI. There are input / output points (or nodes) between the transceiver units and the processing circuits, and across these input / output points, the processing circuits can control the transceiver units, i.e., control the receiver and / or transmitter to exchange received / transmitted data. The transceiver units may include an RF front end, including one or more antennas, amplifiers, RF (Radio Frequency) modulators / demodulators, etc., as a transmitter and receiver. By controlling the transceiver units, the processing circuits can perform control tasks such as transmitting user data and control data provided by the processing circuits, and / or receiving user data and control data that are further processed by the processing circuits. The processing circuits may also be responsible for performing other processes such as judgment, calculation, and measurement. The transmitting unit may be responsible for performing the transmission process and other processes related to the transmission process. The receiving unit may be responsible for performing the reception process and other processes related to the reception process, such as monitoring the channel.

[0112] Various embodiments of the improved transmission procedure are described below. In connection therewith, improved entities such as improved UEs, improved NTN entities, and improved base stations that are involved in the improved transmission procedure are shown. Corresponding methods for the behavior of the UEs, NTN entities, and BSs are also provided.

[0113] According to one embodiment, a network device (for example, NTN entity 160) is provided. The network device comprises a transmitting / receiving unit (for example, the transmitting / receiving unit 170 shown in Figure 10) and a circuit (for example, the processing circuit 180 shown in Figure 10).

[0114] The circuit obtains the round trip time (RTT) for estimating the location of the user equipment (UE). Such location estimation can be applied, for example, in verifying the location reported by the UE. The RTT is obtained based on the user equipment (UE) Rx-Tx time difference. The UE Rx-Tx time difference is the difference between the reception (Rx) timing of a subframe boundary in the UE's downlink frame and the transmission (Tx) timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE. Furthermore, the RTT is obtained based on the gNB Rx-Tx time difference. The gNB Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the gNB's downlink frame and the transmission timing of a subframe boundary in the gNB's uplink frame that is temporally closest to the subframe received by the gNB. Furthermore, the RTT is obtained based on the timing advance (TA) information of the UE, which represents the rounded value of the timing advance. In addition, RTT acquisition is based on the corrected value of the timing advance (TA) information of the UE in question.

[0115] Location estimation can be obtained by the Location Management Function (LMF) described in the above section on <Functional Separation between NG-RAN and 5GC in 5G NR>. The LMF is a network entity in the 5G core network (5GC) (Non-Patent Literature 12). For example, the network entity may be dedicated hardware or a virtual process within a processing unit that performs the LMF function.

[0116] The network device that acquires the RTT may include LMF functionality, or it may provide the acquired RTT to the LMF for purposes such as position estimation.

[0117] The transmitting / receiving unit may receive information about a non-terrestrial network from network nodes. The transmitting / receiving unit may perform reception processing controlled by a circuit. In other words, the circuit may control (instruct) the transmitting / receiving unit, including causing the receiving unit to receive information. Network nodes here include, for example, NTN equipment (satellites, aircraft, etc.), gNB, UE, etc. In particular, the transmitting / receiving unit may receive information based on one or more of the following: UE Rx-Tx time difference, gNB Rx-Tx time difference, TA information, and correction values ​​for the TA information.

[0118] As described above, the rounded value of TA is provided in MAC-CE (see Non-Patent Document 8), which indicates the smallest integer slot greater than or equal to the timing advance value. This will be referred to as the TA-report below. In other words, the TA-report value of the UE is readily available in NTN. For example, the TA-report value is determined as follows:

number

[0119] For example, RTT is determined based on the UE Rx-Tx time difference, the gNB Rx-Tx time difference, the TA report as TA information, and the correction value of said TA information.

[0120] In an exemplary embodiment, the RTT is determined as follows:

number

number

[0121] Figures 13 and 14 show exemplary embodiments where the slot length is the same as the subframe length. In Figure 13, TA1310 is longer than the subframe or slot length of SFj~SFj+3 in the UE uplink frame UE-Tx. Therefore, the TA information, TA-report1311, is rounded up to five subframe lengths, i.e., slots SFj~SFj+4. UE Rx-Tx time difference UE RTTD In the example in Figure 13, this refers to the subframe boundary that is temporally closest to the UE reception timing of the downlink subframe SFi in frame UE-Rx. In Figure 13, the temporally closest subframe boundary is the boundary between subframes SFj+3 and SFj+4, so the UE Rx-Tx time difference UE RTTD This value is greater than zero. Therefore, the available TA report is corrected by only one subframe or one or more slots to obtain an accurate RTT.

[0122] In Figure 13, RTT is given by RTT = TA + gNB RTTD = (TA report -1) + UE RTTD + gNB RTTD This is obtained, where Timing Advance 1310 is the available value in this example, TA - report 1311 and UE Rx-Tx time difference UE RTTD This is obtained by using 1320 with appropriate correction of one subframe. The RTT is obtained by using the obtained TA1310 and the gNB Rx-Tx time difference gNB. RTTD It will be obtained as the sum of 1330 and 1330.

[0123] In Figure 14, TA1410 is greater than the subframe or slot length from SFj to SFj+2 in the UE uplink frame UE-Tx, so it is rounded up, and therefore the TA-report value corresponding to the length of slot SFj to SFj+3 in the UE uplink frame UE-Tx is obtained. In this example, the UE Rx-Tx time difference UE is the result of the temporally closest subframe boundary that points to the boundary between subframes SFj+3 and SFj+4. RTTD 1420 is less than 0. Therefore, in this example, the correction value is zero, and the RTT is RTT = TA + gNB RTTD = TA report + UE RTTD + gNB RTTD This is obtained as follows, where Timing Advance 1410 is the available value TA - report 1411 and UE Rx-Tx time difference UE RTTD This can be obtained by using 1420 with appropriate correction. The RTT is obtained by using the acquired TA1410 and the gNB Rx-Tx time difference gNB. RTTD It will be obtained as a sum with 1430.

[0124] In the examples in Figures 13 and 14 where the slot length is the same as the subframe length, the correction term

number

number

number

number

[0125] In general, the correction value is not limited to the case where the slot length is the same as the subframe length.

[0126] A slot is part of the 5G NR frame configuration, including frames, subframes, and slots. The lengths of frames and subframes are 10ms and 1ms, respectively. A slot is defined as a set of 14 consecutive OFDM symbols. The slot length is determined by the network setting the subcarrier spacing for the bandwidth portion. The bandwidth portion can be set for a single UE or multiple UEs. Depending on the subcarrier spacing of the 14 OFDM symbols, the slot length can be 1ms, 0.5ms, 0.25ms, 0.125ms, and 0.06125ms.

[0127] The RTT (Round-to-Turn Time) may also be determined based on the feeder link delay on the downlink and / or the feeder link delay on the uplink. The feeder link is described above with reference to Figures 6-8. In other words, the RTT determination may include the feeder link delay on the downlink and / or the feeder link delay on the uplink.

[0128] Figure 15 illustrates the feeder link delay in the downlink. The gNB transmits a DL-PRS to the UE via an NTN entity (e.g., a satellite). For example, the gNB transmits the DL-PRS at time t0, and the satellite receives it at time t1. The duration τ0 = t1 - t0 corresponds to the feeder link delay in the downlink. The DL-PRS is received at the UE at time t2.

[0129] Figure 16 illustrates the feeder link delay on the uplink. An exemplary scheduled SRS reception is performed. The gNB sets the UE's SRS signal via SRS resources. SRS resources can be grouped into SRS resource sets. Periodic SRS resource sets are set by RRC signaling. Semi-persistent SRS resource sets are given flexibility by MAC CE control. The gNB transmits an SRS-config at time t0', and the UE receives the SRS-config at time t2'. The UE responds by transmitting an UL-SRS at time t4'. Time t4' is chosen so that the RRC scheduling slot for reception t3' at the gNB is filled. The duration τ3 between the satellite's transmission of the UL-SRS and the gNB's reception corresponds to the feeder link delay on the uplink.

[0130] To improve the estimation of the UE's position, RTT measurements may include corrections for the feeder link delay τ0 in the downlink and / or the feeder link delay τ3 in the uplink. Therefore, residual delay in the service link is included in the RTT. S It can be defined as =RTU-τ0-τ3.

[0131] Network devices may receive feeder link delays on the downlink and uplink from UE, gNB, or NTN entities. Such NTN entities may be proprietary entities such as the NTN Control Center. In other words, information regarding feeder link delays on the downlink and uplink may be available to the UE, gNB, and / or NTN entities. This information may be provided to the network devices by any of the UE, gNB, or NTN entities. In particular, a transceiver included in the network device may receive and provide to the circuit information regarding the feeder link delay τ0 on the downlink and the feeder link delay τ3 on the uplink.

[0132] In multi-RTT, the gNB and UE transmit, for example, a downlink positioning reference signal (DL-PRS) and an uplink sounding reference signal (UL-SRS), respectively. The gNB uses the RRC protocol to configure the UL-SRS for the UE. Meanwhile, the LMF 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 also been extended to support positioning between the UE and the LMF in 5G.

[0133] The UE may transmit measurement results to the LMF using LPP. The gNB may transmit measurement results to the LMF using NR Positioning Protocol A (NRPPa) for UE position estimation. A new next-generation interface between the NG-RAN and the core network introduces a new NR Positioning Protocol A (NRPPa) for transporting positioning information between the NG-RAN and the LMF via the Next-Generation Control Plane Interface (NG-C).

[0134] Based on the following formula, various functional separations between the UE, gNB, and LMF are possible in order to calculate RTT.

number

[0135] For example, UE is UE RTTD TA report The UE may provide the network device with information regarding one or more of the following: the measurement of the data and the feeder link delay. The UE may use LPP to report the measurement results to the network device, for example, the LMF.

[0136] For example, gNB is gNB RTTD TA reportThe gNB may provide the network device with information regarding one or more of the following: the data and the feeder link delay. The gNB may use NRPPa and report the measurements to the network device, e.g., the LMF, for UE location verification.

[0137] Both NRPPa and LPP protocols can be transmitted via the control plane of the NG interface (NG-C) by the Access Mobility Management Function (AMF).

[0138] In the first exemplary embodiment, the network node is connected to the UE via a UE Rx-Tx time difference UE. RTTD and TA information TA report Received from gNB, gNB Rx-Tx time difference gNB RTTD The information is received. In particular, a transmitting / receiving unit included in a network node may receive the information. Alternatively, a circuit included in a network device may instruct the transmitting / receiving unit to receive the information.

[0139] This is illustrated in Figures 17 and 18, where the UE sends TA-report values ​​to the LMF. In Figures 17 and 18, the LMF represents a network device that includes the functions of the LMF. Furthermore, the UE is the UE Rx-Tx time difference UE. RTTD The information is sent to the LMF. The UE's transmission may also be done using an LPP, which is indicated in Figures 17 and 18 by parallel marks on arrows and the label LPP. For example, the list of information sent from the UE to the LMF may be extended to include a full TA report as defined in the Timing Advance Report MAC CE in Non-Patent Literature 8.

[0140] Furthermore, gNB is gNB Rx-Tx time difference gNB RTTDThe data is sent to the LMF. As mentioned above, the gNB can report to a network device, such as the LMF, using NRPPa. NRPPa is indicated in Figures 17 and 18 by parallel marks on arrows and the label NRPPa. In other words, the UE and gNB send data to the LMF individually, and the LMF performs all the necessary processing. RTT and / or RTT s This can be obtained using LMF, for example, by calculation.

[0141] In Figure 17, the UE may optionally transmit a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. In Figure 18, the gNB may optionally transmit a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink.

[0142] For example, Non-Patent Document 13 already defines the field nr-NTA-Offset-r16 in NR-Multi-RTT-SignalMeasurementInformation, which may be modified to indicate the timing advance field signaled in the Timing Advance Report MAC CE element of Non-Patent Document 8. Such modifications may include the addition of new fields used in the Timing Advance Report MAC CE.

[0143] In a second exemplary embodiment, as an addition to the first exemplary embodiment, the gNB may further transmit scheduling information. In other words, the LMF or the network device receives scheduling information from the gNB. Such scheduling information may include K_offset described in the section <Timing Advance and Epoch Time in NTN> above. The value K_offset indicates a scheduling offset used for timing relationships. By comparing the K_offset with the TA - report value, the TA - report value may be verified. In other words, a network device including the gNB and / or the LMF may verify the TA - report value provided by the UE. Thus, the TA - report of the UE may be checked for forgery by comparing it with K_offset. Options for evaluating a non - malicious UE include that K_offset and TA - report fall within the window of N slots, or that K_offset is greater than or equal to TA - report.

[0144] Such an embodiment can improve the security in the acquisition of RTT.

[0145] Figures 19 and 20 illustratively show an additional transmission of K_offset from the gNB to the LMF in addition to the gNB's time difference. Further, the UE transmits the TA - report value and the UE's time difference to the LMF, similar to the examples in Figures 17 and 18. RTTD In addition to the gNB's time difference, the gNB transmits K_offset to the LMF as an example. Further, the UE transmits the TA - report value and the UE's time difference to the LMF, similar to the examples in Figures 17 and 18. RTTD

[0146] In Figure 19, as an option, the UE may transmit the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink. In Figure 20, as an option, the gNB may transmit the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink.

[0147] ​A third exemplary embodiment provides an addition to the first exemplary embodiment, wherein the transmitting / receiving unit further receives TA information from the gNB. In other words, the gNB may transmit the TA-report value to the network device, for example, the LMF. Such embodiments enable a multifaceted check of the TA-report transmitted by the UE to the network device. This check may be performed by the gNB using the K_offset value available to the gNB.

[0148] Figures 25 and 26 illustrate an additional transmission of a TA-report from a gNB to an LMF according to a third exemplary embodiment. For example, the UE sends a TA-report to both the LMF and the gNB. In this exemplary embodiment, the gNB sends the TA-report to the LMF but does not send the K_offset. The LMF may check both TA-reports for tampering. Alternatively, the gNB may use the K_offset to verify the TA-report. Such embodiments can improve security in obtaining the RTT.

[0149] In Figure 25, the UE may optionally transmit a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink. In Figure 26, the gNB may optionally transmit a feeder link delay τ0 on the downlink and a feeder link delay τ3 on the uplink.

[0150] In a fourth exemplary embodiment, the network device may receive a corrected UE Rx-Tx time difference from the UE. RTTD,new This may be based on the UE's RTT UE Rx-Tx time difference and correction of TA information. For example, the corrected UE Rx-Tx time difference UE RTTD,new This is determined as follows:

number

[0151] In other words, the corrected UE Rx-Tx time difference is the UE Rx-Tx time difference UE RTTD This may be calculated as the sum of the corrected TA information. The UE may transmit the corrected UE Rx-Tx time difference via LPP. The LPP modification may be performed in the same manner as in the first exemplary embodiment.

[0152] Furthermore, the network device, and therefore the LMF, may receive the gNB Rx-Tx time difference from the gNB. The gNB may transmit the gNB Rx-Tx time difference via NRPPa.

[0153] Figures 21 and 22 show an example of signaling according to a fourth exemplary embodiment. In Figure 21, the LMF is a corrected UE Rx-Tx time difference UE transmitted from the UE via the LPP. RTTD,new It receives the following. Furthermore, in the example in Figure 21, the gNB transmits the gNB Rx-Tx time difference.

[0154] In the example in Figure 21, the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink are corrected for the UE Rx-Tx time difference UE. RTTD,new It may also include, for example, a corrected UE Rx-Tx time difference UE. RTTD,new This is determined as follows:

number

[0155] In the example shown in Figure 21, the network device, for example, its LMF, determines the RTT as follows:

number

[0156] In other words, the residual RTT includes the sum of the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference.

[0157] Alternatively, arbitrary values ​​for the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink may be provided by the gNB, as in the example described with respect to Figure 18 or Figure 20.

[0158] In Figure 22, the LMF is the corrected UE Rx-Tx time difference UE transmitted from the UE via LPP. RTTD,new The gNB receives the following: Furthermore, in the example in Figure 22, the gNB may also transmit the corrected gNB Rx-Tx time difference, and the corrected gNB Rx-Tx time difference gNB RTTD,new This is called the corrected gNB Rx-Tx time difference.

number

[0159] In other words, the feeder link delays τ0 and τ3 are the gNB Rx-Tx time difference gNB RTTD It can be deducted.

[0160] In the example shown in Figure 22, the network device, for example, LMF, determines the RTT as follows:

number

[0161] 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.

[0162] The signaling according to this fourth exemplary embodiment can reduce overhead by transmitting adaptive (corrected) values ​​for the UE Rx-Tx time difference and / or gNB Rx-Tx time difference.

[0163] In the fifth exemplary embodiment, the network device receives the UE Rx-Tx time difference and corrected TA information from the UE. For example, the UE transmits the UE Rx-Tx time difference and corrected TA information to the network device. The network device in the fifth exemplary embodiment also receives the gNB Rx-Tx time difference from the gNB.

[0164] In particular, the transmitting and receiving unit included in the network node may receive the information transmitted by the UE and / or gNB. Furthermore, the circuitry included in the network device may instruct the transmitting and receiving unit to receive the information.

[0165] For example, corrected TA information may be obtained based on TA information and a correction value for TA information. The corrected TA information may be obtained as the sum of TA information and the correction value for TA information.

number

[0166] Figure 23 shows a first example of a fifth exemplary embodiment. For example, the UE transmits the UE Rx-Tx time difference and the corrected TA information to the network device. The UE may transmit the corrected values ​​of the UE Rx-Tx time difference and / or TA information via the LPP.

[0167] Furthermore, the corrected TA information may include the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink. In this case, the corrected TA information TA as defined above. report,new This can be adjusted by subtracting the feeder link delay value.

number

[0168] Furthermore, the network device, and therefore the LMF, may receive the gNB Rx-Tx time difference from the gNB. The gNB may transmit the gNB Rx-Tx time difference via NRPPa.

[0169] In the first example of the fifth exemplary embodiment, the RTT may be determined as the sum of the UE Rx-Tx time difference, the gNB Rx-Tx time difference, and the corrected TA information.

number

[0170] 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 gNB Rx-Tx time difference, and the corrected TA information.

[0171] Figure 24 shows a second example of the fifth exemplary embodiment. For example, the UE transmits the UE Rx-Tx time difference and the corrected TA information to the network device. The UE may transmit the corrected values ​​of the UE Rx-Tx time difference and / or TA information via the LPP.

[0172] The corrected TA information in the second example may be obtained as the sum of the TA information and the corrected value of the TA information.

number

[0173] Furthermore, the network device, and therefore the LMF, may receive the corrected gNB Rx-Tx time difference from the gNB. The gNB may transmit the gNB Rx-Tx time difference via NRPPa.

[0174] The corrected gNB Rx-Tx time difference is obtained as follows:

number

[0175] In other words, in the second example of the fifth exemplary embodiment, the gNB Rx-Tx time difference gNB RTTD You may subtract the feeder link delays τ0 and τ3 from this.

[0176] In the example shown in FIG. 24, a network device, such as an LMF, determines the RTT as follows. [Number]

[0177] 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.

[0178] In the sixth exemplary embodiment, the network device may receive the UE Rx-Tx time difference, the TA information, and the gNB Rx-Tx time difference from the gNB. In particular, the transceiver included in the network node may receive the information transmitted by the gNB. Also, the circuit 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, the TA information, and the gNB Rx-Tx time difference via NRPPa.

[0179] An example of the signaling according to the sixth exemplary embodiment is shown in FIG. 27. In FIG. 27, the LMF receives the UE Rx-Tx time difference, the TA information, and the gNB Rx-Tx time difference from the gNB. Further, the gNB may transmit, as an option, the feeder link delay τ0 in the downlink and the feeder link delay τ3 in the uplink to the LMF. In the example of FIG. 27, the UE transmits the TA information, such as TA - report, and the UE Rx-Tx time difference to the gNB. The UE may transmit the TA information and the UE Rx-Tx time difference to the gNB using LPP.

[0180] For example, gNB may check for tampering with the TA-report received from the UE by using the K_offset value available in gNB for scheduling. If the TA-report provided by the UE is incorrect, a mismatch between the UE's TA and K_offset may make communication with the UE impossible. Therefore, the TA-report forwarded from gNB to LMF may be more reliable than the TA-report forwarded from the UE.

[0181] 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, for example, as follows:

number

[0182] When considering feeder link delay, the network device may obtain the RTT by subtracting the feeder link delay from the RTT defined above.

number

[0183] In a seventh exemplary embodiment, the network device may receive the RTT from the gNB. In particular, the transceiver included in the network node may receive the RTT transmitted by the gNB. The circuit included in the network device may also instruct the transceiver to receive the RTT. For example, the gNB may receive TA information and the 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 the available information and the acquired information to determine (calculate) the RTT.

[0184] This is illustrated in Figure 28, where the gNB receives TA information and UE Rx-Tx time difference from the UE. The UE may transmit the TA information and 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. If feeder link delay is to be considered, the network device may obtain the RTT by additionally subtracting the feeder link delays τ0 and τ3.

[0185] In such embodiments, as in the sixth exemplary embodiment, the gNB can reduce signaling overhead and improve security by verifying the TA report.

[0186] In the eighth exemplary embodiment, the network device may receive the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference from the gNB. In particular, a transceiver included in the network node may receive such information transmitted by the gNB. Alternatively, a circuit included in the network device may instruct the transceiver to receive such information.

[0187] The corrected UE Rx-Tx time difference may be based on the correction values ​​of the UE Rx-Tx time difference and TA information. In particular, the corrected UE Rx-Tx time difference UE RTTD,new This is UE Rx-Tx time difference UE RTTD And, TA information TA report This can be the sum of the correction value for the TA information.

number

[0188] For example, if the feeder link delays τ0 and τ3 are subtracted and included in the corrected UE Rx-Tx time difference, it will be as follows:

number

[0189] Exemplary signaling according to the eighth exemplary embodiment is shown in FIG. 29. Similar to the sixth and seventh exemplary embodiments, the UE may transmit TA information and UE Rx-Tx time difference to the gNB, for example, using LPP. The gNB may process the received information to obtain the 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 a network device, and thus to the LMF.

[0190] The network device may obtain the RTT S = UE RTTD,new + gNB RTTD as the sum of the corrected UE Rx-Tx time difference and the gNB Rx-Tx time difference.

[0191] Similar to the sixth and seventh exemplary embodiments, the signaling according to the eighth exemplary embodiment may reduce signaling overhead and improve security.

[0192] Similar to the sixth and seventh exemplary embodiments, the gNB may verify the TA - report using the K_offset value.

[0193] As already shown, the estimation of the UE's position may be obtained based on the RTT. The RTT may be obtained according to any of the above-described exemplary embodiments. An overview and exemplary relationship regarding the RTT and the UE's position are described in the <Round-Trip Time> section.

[0194] The obtaining of the estimated value of the UE's position may further include correction for the movement of a non-terrestrial relay (e.g., satellite) and / or the movement of the earth.

[0195] Since the UE's position is a vector with three components, the RTT can be measured at least three times. For UE position estimation in the NTN using multi-RTT with a single satellite in the field of view, the RTT is repeatedly measured using the satellite at different time points. With three RTT measurements, the UE's position appears six times in the system of equations.

[0196] Therefore, the resulting RTT may be the first RTT, and the circuitry included in the network device may further obtain second and third RTTs for UE position estimation. In other words, at least three different time t i The RTT in this case can be obtained by the network device.

[0197] The LMF may additionally correct for the motion of the satellite and Earth before solving for the position of the UE. Such a correction can be thought of as rewinding the satellite and Earth so that the position of the UE appears to be fixed. Such a correction can be made by including an appropriate rotation matrix in the position determination equation.

[0198] For example, the relationship between RTT and UE position in the i-th measurement is given by the following equation.

number

[0199] Furthermore, a network device (e.g., a circuit included in the network device) may verify the reported location of the UE based on the estimated location of the UE based on the acquired RTT.

[0200] For example, a UE (Underground User) may determine its location using GNSS (Global Navigation Satellite System) based location information. However, network operators require reliable location information for UEs connected to the network in order to select the appropriate core network. A malicious UE may spoof the selected PLMN (Public Land Mobile Network). Relying solely on GNSS-based location information reported by UEs is unlikely to be reliable.

[0201] Therefore, location verification may be performed based on estimated location using RTT. Such verification may be performed independently of location information reported by the UE. UE location information may be considered verified if the reported UE location matches network-based assessments within 5-10 km (i.e., similar in size to a ground macrocell). This enables country identification and selection of appropriate core networks to support all regulatory services (i.e., emergency calls, lawful interception, public alerts, billing / charging).

[0202] Figure 30 is a flowchart of an exemplary method performed by a network device. In particular, the network device may receive information based on one or more of the following: UE Rx-Tx time difference, gNB Rx-Tx time difference, TA information, and correction values ​​for the TA information (S3010).

[0203] Based on the received information, the Round-Trip Time (RTT) may be obtained. A method for obtaining round-trip time by network equipment for non-terrestrial networks is provided. In particular, the RTT is obtained for the estimation of the UE's location (S3020). The acquisition of the RTT is as follows: - User Equipment (UE) Rx-Tx time difference, which is the time difference between the reception timing of a subframe boundary in the UE's downlink frame and the transmission timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE. -gNB Rx-Tx time difference, which is the time 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 that is temporally closest to the subframe received by the gNB. - UE Timing Advance (TA) information, which indicates the rounded value of the Timing Advance, and TA information. - Correction values ​​for Timing Advance (TA) information, Based on.

[0204] The location of the UE may be estimated as described above (S3030). Furthermore, the location of the UE, for example, the location reported by the UE, may be verified based on the estimated location (S3040).

[0205] This disclosure is not limited to network devices that include LMF functionality. In Figures 17-29, the LMF functionality provided by the LMF block may be included in a network device. For example, a network device may obtain RTT based on information provided by the UE and / or gNB and provide RTT to an LMF that may be hosted on another device.

[0206] This disclosure can be implemented by software, hardware, or software that interacts with hardware. Each functional block used in the description of each embodiment described above can be implemented partially or entirely by an LSI (Large Scale Integration) such as an integrated circuit (IC), and each process described in each embodiment may be controlled partially or entirely by the same LSI or a combination of LSIs. The LSI may be formed as individual chips, or a single chip may be formed to include some or all of the functional blocks. The LSI may include data inputs and outputs coupled thereto. Here, LSIs may be called ICs, system LSIs, super LSIs, or ultra LSIs depending on the degree of integration. However, the technology for realizing integrated circuits is not limited to LSIs, and may be implemented using dedicated circuits, general-purpose processors, or application-specific processors. Furthermore, a Field Programmable Gate Array (FPGA) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells arranged inside the LSI, may be used. This disclosure can be implemented as digital processing or analog processing. As a result of advancements in semiconductor technology and other derivative technologies, if future integrated circuit technology replaces LSIs, functional blocks can be integrated using future integrated circuit technology. Biotechnology can also be applied.

[0207] This disclosure can be implemented by any type of device, apparatus, or system having communication capabilities, referred to as a communication apparatus.

[0208] The communication device may have a transmitting / receiving section and a processing / control circuit. The transmitting / receiving section may have a receiving section and a transmitting section, and / or function as both a receiving and a transmitting section. The transmitting / receiving section as a transmitting and receiving section may include an RF (Radio Frequency) module including an amplifier, an RF modulation / demodulation section, and one or more antennas.

[0209] Some non-exclusive examples of such communication devices include telephones (e.g., 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, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, and vehicles providing communication capabilities (e.g., automobiles, airplanes, ships), as well as various combinations thereof.

[0210] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0211] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0212] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0213] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0214] <Overview of Embodiments> Corresponding to the network nodes and related further examples and embodiments described above, the Disclosure provides corresponding methods performed by network nodes or their processing circuits.

[0215] A network device is provided, comprising a transmitting / receiving unit and a circuit for acquiring round trip time (RTT) for estimating the location of user equipment (UE), wherein the acquisition of the RTT is based on (i) a UE Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in the downlink frame of the UE and the transmission timing of a subframe boundary in the uplink frame of the UE that is temporally closest 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 the downlink frame of the gNB and the transmission timing of a subframe boundary in the uplink frame of the gNB that is temporally closest to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, which indicates a rounded value of the timing advance value; and (iv) a correction value of the TA information.

[0216] For example, the circuit further obtains an estimate of the UE's position based on the acquired RTT.

[0217] For example, obtaining an estimate of the UE's position further includes making corrections for the movement of non-terrestrial relay devices and / or the movement of the Earth.

[0218] In an exemplary embodiment, the acquired RTT is a first RTT, and the circuit further acquires a second RTT and a third RTT for estimating the location of the UE.

[0219] In some embodiments, the circuit further verifies the reported location of the UE based on the estimated location of the UE based on the acquired RTT.

[0220] For example, RTT is determined as follows:

number

number

[0221] In some embodiments, the acquisition of the RTT is further based on the downlink feeder link delay and / or the uplink feeder link delay.

[0222] In an exemplary embodiment, the transmitting / receiving unit receives the downlink feeder link delay and the uplink feeder link delay from the UE, the gNB, or the NTN entity.

[0223] For example, the transmitting and receiving unit further receives the UE Rx-Tx time difference from the UE, receives the TA information from the UE, and receives the gNB Rx-Tx time difference from the gNB.

[0224] For example, the transmitting and receiving unit further receives scheduling information from the gNB.

[0225] For example, the transmitting and receiving unit further receives the TA information from the gNB.

[0226] In some embodiments, the transmitting / receiving unit further receives the corrected UE Rx-Tx time difference from the UE, and based on the corrected UE Rx-Tx time difference, the TA information, and the correction value of the TA information, the transmitting / receiving unit receives the gNB Rx-Tx time difference from the gNB.

[0227] For example, the transmitting and receiving unit further receives the UE Rx-Tx time difference and corrected TA information from the UE, and receives the gNB Rx-Tx time difference from the gNB.

[0228] For example, the transmitting and receiving unit further receives the UE Rx-Tx time difference, the TA information, and the gNB Rx-Tx time difference from the gNB.

[0229] As an exemplary embodiment, the transmitting and receiving unit further receives the UE Rx-Tx time difference, the gNB Rx-Tx time difference, the TA information, and the RTT based on the correction value of the TA information from the gNB.

[0230] For example, the transmitting and receiving unit further receives from the gNB the UE Rx-Tx time difference, the TA information, and the corrected UE Rx-Tx time difference based on the correction value of the TA information, as well as the gNB Rx-Tx time difference.

[0231] A method is provided for obtaining round trip time (RTT) by network equipment for a non-terrestrial network, the method comprising the step of obtaining the RTT for estimating the location of user equipment (UE), the acquisition of the RTT being 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 that is temporally closest 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 a gNB and the transmission timing of a subframe boundary in an uplink frame of the gNB that is temporally closest to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, which indicates a rounded value of the timing advance value; and (iv) a correction value of the TA information.

[0232] This method may be performed on the processing circuit of a network device or by an integrated circuit. In such cases, instead of the receiving and transition steps, the method includes providing data for (wireless) transmission to a transmitting / receiving unit (or simply an output unit) and receiving data (e.g., information based on RTT acquisition) from the transmitting / receiving unit (or simply an input unit).

[0233] This disclosure provides an integrated circuit (IC) for obtaining round trip time (RTT) for estimating the location of user equipment (UE), the RTT being obtained based on: (i) the UE Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in the UE's downlink frame and the transmission timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE; (ii) the gNB Rx-Tx time difference, which is the difference between the reception timing of a subframe boundary in the gNB's downlink frame and the transmission timing of a subframe boundary in the gNB's uplink frame that is temporally closest to the subframe received by the gNB; (iii) timing advance (TA) information of the UE, which indicates a rounded value of the timing advance; and (iv) a correction value of the TA information. The IC further comprises an input unit from which system information is provided by a receiving unit. Such an input unit may be connectable to, or may be connected to, a transmitting / receiving unit that receives the information in an actual implementation.

[0234] This disclosure further provides program code that, when executed on one or more processors, causes one or more processors to perform any of the methods described above. The program code may be stored in a non-temporary medium.

[0235] This disclosure provides a communication system comprising the aforementioned network device, one or more user devices, and one or more gNBs. It may further include one or more NTN entities.

Claims

1. Network equipment for non-terrestrial networks, Transmitter / receiver unit, A circuit that acquires round trip time (RTT) for estimating the location of user equipment (UE), Equipped with, The acquisition of the aforementioned RTT is - The UE Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the UE's downlink frame and the transmission timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE. - The gNB Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the downlink frame of the gNB and the transmission timing of a subframe boundary in the uplink frame of the gNB that is temporally closest to the subframe received by the gNB. - Timing Advance (TA) information of the aforementioned UE, which includes TA information indicating the rounded value of the timing advance value, - The correction value of the TA information, Based on, Network device.

2. The circuit further obtains an estimated value of the position of the UE based on the acquired RTT. The network device according to claim 1.

3. Obtaining an estimated position of the aforementioned UE further includes making corrections for the movement of non-terrestrial relay equipment and / or the movement of the Earth. The network device according to claim 2.

4. The acquired RTT is a first RTT, and the circuit further acquires a second RTT and a third RTT for estimating the position of the UE. The network device according to claim 2.

5. The circuit further verifies the reported position of the UE based on the estimated position of the UE obtained from the RTT. The network device according to claim 2.

6. The aforementioned RTT is, [Number 30] Determined by, Here, UE RTTD This represents the UE Rx-Tx time difference, and gNB RTTD represents the gNB Rx-Tx time difference, and TA report This represents the TA information, [Number 31] This represents the correction value of the TA information, SD represents the slot length, and ceil() represents the ceiling function that returns the smallest integer greater than or equal to the argument. The network device according to claim 1.

7. The acquisition of the aforementioned RTT is further based on the downlink feeder link delay and / or uplink feeder link delay. The network device according to claim 1.

8. The transmitting and receiving unit receives the downlink feeder link delay and the uplink feeder link delay from the UE, the gNB, or the NTN entity. The network device according to claim 7.

9. The aforementioned transmitting and receiving unit further, The UE receives the UE Rx-Tx time difference from the UE, The TA information is received from the UE. The time difference between the gNB Rx and Tx is received from the gNB. The network device according to claim 1.

10. The transmitting and receiving unit further receives scheduling information from the gNB. The network device according to claim 9.

11. The transmitting and receiving unit further receives the TA information from the gNB. The network device according to claim 9.

12. The aforementioned transmitting and receiving unit further, The corrected UE Rx-Tx time difference is received from the UE, and the corrected UE Rx-Tx time difference is calculated based on the UE Rx-Tx time difference, the TA information, and the correction value of the TA information. The time difference between the gNB Rx and Tx is received from the gNB. The network device according to claim 1.

13. The aforementioned transmitting and receiving unit further, The UE receives the UE Rx-Tx time difference and the corrected TA information from the UE. The time difference between the gNB Rx and Tx is received from the gNB. The network device according to claim 1.

14. The aforementioned transmitting and receiving unit further, From the aforementioned gNB, - The aforementioned UE Rx-Tx time difference, - The aforementioned TA information, and - The gNB Rx-Tx time difference To receive The network device according to claim 1.

15. The aforementioned transmitting and receiving unit further, The RTT based on the UE Rx-Tx time difference, the gNB Rx-Tx time difference, the TA information, and the correction value of the TA information is received from the gNB. The network device according to claim 1.

16. The aforementioned transmitting and receiving unit further, From the aforementioned gNB, - The corrected UE Rx-Tx time difference based on the UE Rx-Tx time difference, the TA information, and the correction value of the TA information, - The aforementioned gNB Rx-Tx time difference, To receive The network device according to claim 1.

17. A method for obtaining round trip time (RTT) using network equipment for a non-terrestrial network, The process includes the step of obtaining the RTT for estimating the location of the user equipment (UE), The acquisition of the aforementioned RTT is - The UE Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the UE's downlink frame and the transmission timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE. - The gNB Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the downlink frame of the gNB and the transmission timing of a subframe boundary in the uplink frame of the gNB that is temporally closest to the subframe received by the gNB. - Timing Advance (TA) information of the aforementioned UE, which includes TA information indicating the rounded value of the timing advance value, - The correction value of the TA information, Based on, method.

18. To estimate the location of the user equipment (UE), the round trip time (RTT) is obtained. The acquisition of the aforementioned RTT is - The UE Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the UE's downlink frame and the transmission timing of a subframe boundary in the UE's uplink frame that is temporally closest to the subframe received by the UE. - The gNB Rx-Tx time difference is the difference between the reception timing of a subframe boundary in the downlink frame of the gNB and the transmission timing of a subframe boundary in the uplink frame of the gNB that is temporally closest to the subframe received by the gNB. - Timing Advance (TA) information of the aforementioned UE, which includes TA information indicating the rounded value of the timing advance value, - The correction value of the TA information, Based on, Integrated circuit (IC).

19. When executed on one or more processors, the one or more processors are made to perform the method according to claim 17. Program code.

20. A network device according to any one of claims 1 to 16, One or more user devices, One or more gNBs, Equipped with, Communication system.

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