User equipment and methods in user equipment

Abstract

The present disclosure relates to a user equipment (3), an access network node (6), and methods implemented thereby. A method is disclosed that is implemented by a user equipment (UE) for communicating over a non-terrestrial based network. The method includes receiving configuration information identifying pre-configured uplink resources for use by the UE (3) in a radio resource control (RRC) idle state, validating whether the configuration information is still valid, and determining whether to transmit data using the pre-configured uplink resources according to the validation.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system and its devices operating according to 3rd Generation Partnership Project (3GPP (registered trademark)) specifications or specifications equivalent to 3GPP specifications or specifications derived from 3GPP specifications. The present disclosure is particularly relevant to improvements in communication using preconfigured resources in so-called "next generation" ("5G") systems that employ a non-terrestrial portion including aerial or space network nodes, although not exclusively.

Background Art

[0002] Under 3GPP specifications, NodeB (or "eNB" in LTE and "gNB" in 5G) is a base station for a communication device to connect to a core network and communicate with other communication devices or remote servers. The communication device may be, for example, a mobile communication device such as a mobile phone, smartphone, smartwatch, personal digital assistant, laptop / tablet computer, web browser, e-book reader, etc. The end-user communication device is generally referred to as User Equipment (UE) and may be operated by a human or may include an automated device. Such mobile (or generally fixed) devices are usually operated by a user (thus, they are often collectively referred to as user equipment "UE"), but it is also possible to connect so-called Internet of Things (IoT) devices and similar Machine Type Communication (MTC) devices to the network. For simplicity, this application uses the term base station to refer to such a base station and the terms mobile device or UE to refer to such a communication device.

[0003] The latest developments in 3GPP standards cover evolving communication technologies that are expected to support a wide range of applications and services, including MTC, IoT / Industrial IoT (IIoT) communications, vehicle-to-vehicle communications and autonomous vehicles, high-resolution video streaming, and smart city services. To enhance support for MTC devices, 3GPP introduced the “eMTC” (enhanced MTC) UE category in Release 12, defining the first low-complexity UE category 0 (Cat-0). Cat-0 supports a reduced peak data rate of 1 Mbps, single antenna, and half-duplex frequency division duplex (HD FDD) operation. 3GPP Release 13 introduced support for the so-called “Cat-M1” UE, enabling further cost savings through a reduced transmit and receive bandwidth of 1.08 MHz and the introduction of a lower UE power class of 20 dBm in addition to the 23 dBm power class. Cat-M1 UEs operate in narrowband (NB) and may also support Coverage Enhancement (CE) operation. LTE Releases 14 and 15 defined a new UE category, Cat-M2, with a transmit and receive bandwidth of 5 MHz.

[0004] In Release 13, 3GPP launched its efforts toward Narrowband Internet of Things (NB-IoT) UEs with a full 180kHz baseband bandwidth. NB-IoT supports operation on anchor carriers (where the UE assumes specific signals and channels to be transmitted) and on non-anchor carriers (where such signals and channels are not assumed to be transmitted). Similar to eMTC, NB-IoT expands system coverage by leveraging increased acquisition time and time iteration. However, unlike MTC, NB-IoT does not support measurement reporting and handover in connected mode.

[0005] 3GPP is also working on defining the infrastructure for integrated satellite and terrestrial networks. For example, 3GPP Technical Report (TR) 36.763 V17.0.0 is a study on narrowband Internet of Things (NB-IoT) / enhanced machine-type communications (eMTC) support for non-terrestrial networks in Release 17. The term Non-Terrestrial Network (NTN) refers to a network or segment of a network that uses airborne or spacecraft for transmission. Satellites refer to spacecraft in geostationary Earth Orbit (GEO) or non-geostationary Earth Orbit (NGEO), such as Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and Highly Elliptical Orbit (HEO). Airborne vehicles refer to high-altitude platforms (HAPs), including unmanned aircraft systems (UAS), tethered UAS, lighter than air (LTA) UAS, and heavy than air (HTA) UAS, all of which typically operate in a quasi-steady state at altitudes of 8-50 km.

[0006] 3GPPTR38.811 V15.4.0 is a study on new radios supporting such non-terrestrial networks. This study includes, among other things, NTN deployment scenarios and related system parameters (e.g., architecture, altitude, orbit, etc.), as well as a description of the adaptation of the 3GPP channel model to non-terrestrial networks (propagation conditions, mobility, etc.). 3GPPTR38.821 V16.1.0 provides further details on NTN.

[0007] NTN access typically features the following elements (in particular): NTN terminal: May refer to a 3GPP UE or terminal specific to a satellite system when the satellite does not directly provide services to the 3GPP UE. A service link refers to a wireless link between user equipment and a spatial / airborne platform (which may be added to a wireless link with a ground-based RAN). Space or aerial platform. A gateway ("NTN Gateway") connects a satellite or airborne access network to the core network. It will be understood that gateways are most likely to be located in the same place as base stations. A feeder link refers to the wireless link between a gateway and a spatial / airborne platform.

[0008] A satellite or aircraft may generate several beams over a given area to supply to each NTN cell. These beams typically have an elliptical footprint on the Earth's surface.

[0009] 3GPP intends to support the following three types of NTN beams or cells: Earth-fixed cells (e.g., GEO satellites and HAPS) feature beams (one or more) that always cover the same geographical area. Quasi-Earth-fixed cells (e.g., NGEO satellites that generate steerable beams) featuring (one or more) beams that cover one geographic area over a finite period and different geographic areas over different periods, and A mobile Earth cell (e.g., an NGEO satellite that generates fixed or unsteering beams) featuring (one or more) beams covering one geographic area at any given moment and different geographic areas at another moment.

[0010] For a satellite or aircraft that maintains a fixed position with respect to a given point on Earth, such as a GEO and UAS, the beam footprint is fixed to the Earth. For satellites orbiting the Earth (e.g., LEO) or in elliptical orbits around the Earth (e.g., HEO), the beam footprint may move across the Earth along with the movement of the satellite or aircraft in its orbit. Alternatively, the beam footprint may be temporarily fixed to the Earth (or quasi-Earth), in which case an appropriate beampointing mechanism (mechanical or electronic steering) may be used to compensate for the movement of the satellite or aircraft.

[0011] LEO satellites may have steerable beams, in which case the beams are temporarily directed to a substantially fixed footprint on Earth. In other words, the beam footprints (representing NTN cells) remain stationary on the ground for a certain period of time before changing their focal area to another NTN cell (due to the satellite's movement in orbit). From a cell coverage / UE perspective, even when these beams service the same terrestrial area (having the same footprint), a different Physical Cell Identifier (PCI) and / or Synchronization Signal / Physical Broadcast Channel (PBCH) block (SSB) must be assigned after each service link change, resulting in cell changes occurring regularly at discrete intervals. LEO satellites without steerable beams produce beams (cells) that constantly sweep across the ground as the satellite moves along its orbit, and as with steerable beams, service link changes and consequently cell changes occur regularly at discrete intervals. Similar to changes in service links, changes in feeder links also occur at regular intervals due to the satellite's movement in orbit.

[0012] Non-Geostationary Orbit (NGSO) satellites are a type of NGEO satellite (e.g., LEO or MEO satellites) that features an Earth-centered orbit with an orbital period that does not coincide with the Earth's rotation on its axis. This means there is relative movement between the NGSO satellite and the Earth, resulting in a satellite (cell) coverage area that can change over time.

[0013] As described in 3GPPTR36.763, 3GPP's current approach is to make existing cellular IoT features defined up to Release 16 (e.g., support for 4G / 5G core networks, Early Data Transmission (EDT), Preconfigured Uplink Resource (PUR), Self-Organizing Network (SON) functionality, etc.) available for use in NTN deployments, provided they do not require significant modifications to be adapted to NTN.

[0014] Looking at a specific case of PUR, this feature targets UEs in a Radio Resource Control (RRC) idle state, where RRC idle UEs can obtain uplink permission by performing uplink transmissions without performing time- and energy-consuming procedures (e.g., random access) using their associated (enabled) PUR configuration. The network can configure appropriate PUR resources for the UE when the UE's RRC connection is released. Then, while in idle mode, if the UE has uplink data to transmit, the UE checks whether a PUR resource is available in the current cell and transmits the data using the pre-configured resource. When checking whether an appropriate PUR resource is available, the UE checks whether it has a valid timing advance / timing alignment (which can be determined using the associated timer) and whether the fluctuation in the signal level within the cell (given by the associated Reference Signal Received Power, i.e., RSRP) exceeds a configured threshold.

[0015] However, the inventors realized that current standards define procedures developed with terrestrial networks in mind, and that these procedures may not be directly applicable to non-terrestrial networks.

[0016] For example, in the case of NGSO cells (cells serviced via NGSO satellites) and similar cells with discontinuous coverage, even if the same cell (or another cell) can become available again in a predictable manner (e.g., following a regular pattern or any other prior known pattern), the movement of satellites in their orbits can invalidate timing advance / timing alignment and / or exceed the signal variation threshold relatively quickly. Thus, the usefulness of PUR in some systems, including non-ground portions, can be severely limited and may result in increased power consumption and network load at the UE. For IoT devices or eMTC devices, it is crucial that power consumption can be reduced, which can shorten the time they spend on uplink transmission procedures and extend the lifespan of such devices. [Prior art documents] [Non-patent literature]

[0017] [Non-Patent Document 1] 3GPP Technical Report (TR)36.763 V17.0.0 [Non-Patent Document 2] 3GPP TR38.811 V15.4.0 [Non-Patent Document 3] 3GPP TR38.821 V16.1.0 [Non-Patent Document 4] 3GPP TR36.763 [Non-Patent Document 5] 3GPP Technical Specification (TS) 36.331 [Non-Patent Document 6] 3GPP TS38.300 V16.8.0 [Non-Patent Document 7] 3GPP TS37.340 V16.8.0 [Overview of the Initiative] [Problems that the invention aims to solve]

[0018] Therefore, there is a need to provide an improved procedure for pre-configuring uplink resources for user equipment using a cell (e.g., camping on) served by non-terrestrial nodes such as satellites and UAS. The present disclosure seeks to provide a method and related apparatus for addressing (at least in part) the above problems or at least mitigating them. For the sake of efficiency in the understanding of those skilled in the art, the present disclosure is described in detail in the context of 3GPP systems (LTE / 5G networks including NTN), but the principles of the present disclosure can also be applied to other systems.

Means for Solving the Problems

[0019] In one aspect, the present disclosure provides a method performed by a user equipment (UE) for communicating via a non-terrestrial network, the method including receiving configuration information identifying pre-configured uplink resources for use by the UE in a radio resource control (RRC) idle state, verifying whether the configuration information is still valid, and determining whether to transmit data using the pre-configured uplink resources according to the verification.

[0020] In one aspect, the present disclosure provides a method performed by an access network node for communicating with a user equipment (UE) via a non-terrestrial network, the method including transmitting configuration information identifying pre-configured uplink resources for use by the UE in a radio resource control (RRC) idle state, and transmitting received information indicating whether the configuration information is valid, the information being used by the UE to verify whether the configuration information is still valid.

[0021] In one embodiment, the Disclosure provides a user equipment (UE) for communicating over a non-terrestrial network, the UE comprising means for receiving configuration information identifying pre-configured uplink resources for use by the UE in a radio resource control (RRC) idle state, means for authenticating whether the configuration information is still valid, and means for determining, in accordance with the authentication, whether to transmit data using the pre-configured uplink resources.

[0022] In one embodiment, the Disclosure provides an access network node for communicating with a user equipment (UE) over a non-terrestrial network, the access network node comprising means for transmitting configuration information that identifies a pre-configured uplink resource for use by the UE in a radio resource control (RRC) idle state, and means for transmitting received information indicating whether the configuration information is valid, the information being used by the UE to authenticate whether the configuration information is still valid. [Effects of the Invention]

[0023] Aspects of this disclosure extend to corresponding systems and computer program products such as computer-readable storage media storing instructions, which are operable to program a programmable processor to perform the methods described above or possible methods described in the claims, and / or to program a computer appropriately adapted to provide the apparatus described in any of the claims.

[0024] Each feature disclosed herein (this term includes the claims) and / or each feature shown in the drawings may be incorporated into this disclosure independently of (or in combination with) any other disclosed and / or illustrated features. In particular, any feature of a claim dependent on a particular independent claim may be introduced into that independent claim in any combination or individually.

[0025] Herein, embodiments of the present disclosure will be described as examples with reference to the attached drawings. [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram of a mobile (cellular or wireless) telecommunications system to which embodiments of the present disclosure may be applied.

[0027] [Figure 2] Figure 1 is a schematic block diagram of mobile devices that form part of the system shown.

[0028] [Figure 3] This is a schematic block diagram of an access network node (e.g., base station) or NTN node (e.g., satellite / UAS platform) that forms part of the system shown in Figure 1.

[0029] [Figure 4] This is a schematic block diagram of a core network node (e.g., MME) that forms part of the system shown in Figure 1.

[0030] [Figure 5] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0031] [Figure 6] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0032] [Figure 7] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0033] [Figure 8] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0034] [Figure 9]This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0035] [Figure 10] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0036] [Figure 11] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0037] [Figure 12] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0038] [Figure 13] This disclosure is a schematic diagram of some exemplary methods that may be implemented in the system shown in Figure 1.

[0039] [Figure 14] Figure 1 is a schematic diagram of several exemplary architectural options for providing NTN features in the system shown. [Modes for carrying out the invention]

[0040] <Overview>

[0041] Figure 1 is a schematic diagram of a mobile (cellular or wireless) telecommunications system 1 to which embodiments of the present disclosure may be applied.

[0042] In this system 1, users of mobile devices 3 (UEs) can communicate with each other and with other users via satellites 5 and / or base stations 6 of each access network node, and the data network 7, using appropriate 3GPP radio access technology (RAT), such as E-UTRA (4G) and / or NR (5G) RAT. In the case of E-UTRA RAT, base station 6 may be called "eNB" or "ng-eNB," and in the case of NR RAT, base station 6 may be called "gNB." UE3 may include an NB-IoT or MTC UE, or may include appropriate NB-IoT or MTC functionality. As will be understood by those skilled in the art, Figure 1 shows three UE3, one satellite 5, and one base station 6 for illustrative purposes, but the system will typically include other satellite / UAS platforms, base station / RAN nodes, and mobile devices (UEs) when implemented.

[0043] It will be understood that several base stations 6 form a (radio) access network, i.e., (R)AN, and several NTN nodes 5 (satellite and / or UAS platforms) form a non-terrestrial network (NTN). Each NTN node 5 is connected to an appropriate gateway (located in the same place as the base station 6 in this case) using a so-called feeder link, and then connected to its respective UE3 via a corresponding service link. Thus, when serviced by an NTN node 5, a mobile device 3 communicates data to the base station 6 via the NTN node 5 using the appropriate service link (between the mobile device 3 and the NTN node 5) and the feeder link (between the NTN node 5 and the gateway / base station 6). In other words, NTN forms part of the (R)AN, but can also provide satellite communication services independently of E-UTRA and / or 5G communication services.

[0044] Although not shown in Figure 1, adjacent base stations 6 are connected to each other via appropriate inter-base station interfaces (e.g., so-called "X2" interfaces, "Xn" interfaces, etc.). Base stations 6 are also connected to data network nodes via appropriate interfaces (e.g., so-called "S1", "NG-C", "NG-U" interfaces, etc.).

[0045] The data (or core) network 7 (e.g., EPC in the case of LTE, NGC in the case of NR / 5G) typically includes logical nodes (or "functions") for supporting communications in the telecommunications system 1, including (among other) subscriber management, mobility management, billing, security, and call / session management. Typically, the data network 7 includes user plane entities and control plane entities. The so-called 4G Mobility Management Entity (MME), or 5G Access and Mobility Function (AMF), is responsible for handling connectivity and mobility management tasks for mobile devices 3, including configuring power-saving mechanisms. The data network 7 also connects to other data networks, such as the Internet and similar Internet Protocol (IP) based networks (not shown in Figure 1).

[0046] Each NTN node 5 controls several directional beams (at least one beam) that may be supplied through it to an associated NTN cell. Specifically, each beam has an associated footprint on the Earth's surface corresponding to an NTN cell. Each NTN cell (beam) has associated physical cell identification information (PCI) and / or beam identification information. The beam footprint may move as the NTN node 5 moves along its orbit. Alternatively, the beam footprint may be fixed to the Earth, in which case an appropriate beam pointing mechanism (mechanical or electronic steering) may be used to compensate for the movement of the NTN node 5.

[0047] The network also supports communication for idle UE3s using pre-configured uplink resources (PURs). Specifically, a PUR may be configured for a compatible UE3 when base station 6 releases its RRC connection for that UE3. Details of applicable PUR configurations are included in messages for releasing the UE connection (e.g., RRCConnectionRelease messages) or messages for RRC reconfiguration (e.g., RRCReconfiguration / RRCConnectionReconfiguration messages). The PUR configuration (or at least part of it) is included in one or more appropriate information elements of the message.

[0048] With PUR configured, idle UEs can transmit data over the PUR resource, thereby reducing the need for additional signaling related to scheduling UE transmissions, which is also beneficial from a UE power consumption perspective. However, before transmitting using PUR, UE3 verifies whether the resource is available, i.e., whether the relevant PUR configuration is still valid.

[0049] More specifically, in terrestrial networks, before transmitting using PUR, UE3 checks whether the associated timing advance or timing alignment value is still valid (i.e., whether the so-called pur-TimeAlignmentTimer, if configured, has expired), and (if applicable) whether the fluctuation in the current cell's reference signal received power exceeds a configured threshold.

[0050] In the non-terrestrial portion of Network 1, satellite coverage can be discontinuous, particularly for IoT devices located in remote areas. This means that timing alignment is no longer valid when UE3 is outside the coverage area or when UE3 selects a new serving cell.

[0051] This disclosure discusses various ways (or solutions) that allow UE3 to be configured to use PUR composed of a given cell in another cell, even within a cell with discontinuous coverage (such as a specific NTN cell).

[0052] In the first solution, the PUR configuration is associated with multiple cells (identified, for example, by a cell list), and UE3 is configured to continue using the PUR configuration across multiple cells.

[0053] In the second solution, UE3 is configured to use its PUR configuration from the previous cell within a new serving cell that is determined to be either identical to or a replacement for the previous cell. Cells can be determined to be identical based on their carrier frequency, cell identifier, system information, and / or any other cell parameters. In this case, it is not necessary to provide UE3 with a list of cells, as UE3 may have other methods for determining whether the PUR configuration is available in the new cell.

[0054] In the third solution, PUR is active as long as UE3 is covered by the satellite (regardless of which cell). In this case, the network sends information about the coverage provided via the associated cell (coverage start time, end time, etc.) to UE3 so that it can determine the (one or more) windows of coverage in which UE3 can use PUR.

[0055] In the fourth solution, PUR may be effective within a configured area. The area may be determined based on a reference position and thresholds, and / or on any other information (such as beam footprint size) that allows UE3 to determine the area to be served by satellite 6.

[0056] In the fifth solution, the effectiveness of the PUR configuration can be controlled by changing how UE3 handles associated timers while being serviced by the non-terrestrial portion of the network.

[0057] Beneficial in this regard, these solutions enable UE3 to apply the appropriate PUR configuration across multiple cells and transmit uplink data in a fast and efficient manner.

[0058] <User Equipment (UE)> Figure 2 is a block diagram showing the main components of the mobile device (UE) 3 shown in Figure 1. As illustrated, the UE 3 includes a transceiver circuit 31 capable of transmitting signals to and receiving signals from one or more nodes connected via one or more antennas 33. Although not necessarily shown in Figure 2, the UE 3 naturally has all the usual functions of a conventional mobile device (such as a user interface 35 and one or more Universal Subscriber Identity Modules (USIMs) 36), which may be provided by one or any combination of hardware, software, and firmware as needed. The control unit 37 controls the operation of the UE 3 according to software stored in memory 39. The software may be pre-installed in memory 39 and / or downloaded, for example, via a telecommunications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 41, a communication control module 43, and a positioning module 45 (optional in some UEs).

[0059] The communication control module 43 is responsible for processing (generating / transmitting / receiving) signaling messages and uplink / downlink data packets between the UE3 and other nodes, including the NTN node 5, the (R)AN node 6, and core network nodes. Signaling may include control signaling related to communication using pre-configured uplink resources (over a non-terrestrial network). If the UE3 is configured to operate in eMTC / IoT / NB-IoT / IoT-NTN mode, the operation of the communication control module 43 is adapted accordingly.

[0060] If present, the positioning module 45 is responsible for determining the position of UE3 based, for example, on Global Navigation Satellite System (GNSS) signals.

[0061] <Access network nodes (base stations / gateways) and NTN nodes> Figure 3 is a block diagram showing the main components of the access network node 6 (e.g., a base station (gNB) or gateway) shown in Figure 1. Figure 3 is also applicable to NTN node 5 (satellite or UAS platform). As shown, the access network node 6 / NTN node 5 includes transceiver circuitry 51 capable of transmitting and receiving signals from connected (one or more) UE3s via one or more antennas 53, and transmitting and receiving signals from other network nodes (directly or indirectly) via network interface 55. Signals may be transmitted and received from (one or more) UE3s directly and / or via (one or more) NTN nodes 5, as needed. Network interface 55 typically includes appropriate base station-base station interfaces (e.g., X2 / Xn) and appropriate base station-core network interfaces (e.g., S1 / NG-C / NG-U), although in the case of NTN node 5, some of these may be optional. The control unit 57 controls the operation of the access network node 6 / NTN node 5 according to the software stored in the memory 59. The software may be pre-installed in the memory 59 and / or may be downloaded, for example, via the telecommunications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 61 and a communication control module 63.

[0062] The communication control module 63 is responsible for processing (generating / transmitting / receiving) signaling between the access network node 6 / NTN node 5 and other nodes such as UE3, other NTN nodes 5 / base stations 6, and core network nodes (e.g., MME9). The signaling may include control signaling related to communication using pre-configured uplink resources (over a non-terrestrial network).

[0063] <Core Network Node> Figure 4 is a block diagram showing the main components of the core network node shown in Figure 1. As shown, the core network node includes transceiver circuitry 71 capable of transmitting signals to and receiving signals from other network nodes (directly or indirectly) via a network interface 75. The network interface 75 typically includes an appropriate core network-base station interface (e.g., S1 / NG-C / NG-U). The control unit 77 controls the operation of the core network node according to software stored in memory 79. The software may be pre-installed in memory 79 and / or downloaded, for example, via the telecommunications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 81 and a communication control module 83.

[0064] The communication control module 83 is responsible for processing (generating / transmitting / receiving) signaling between the core network nodes and the UE3, access network nodes, and other core network nodes. The signaling may include control signaling related to communication using pre-configured uplink resources (over a non-terrestrial network).

[0065] <Detailed explanation> The following describes some exemplary steps (referred to as Solutions 1-5) performed by the system nodes shown in Figure 1 to communicate using pre-configured uplink resources.

[0066] However, before discussing the details of these procedures in the context of non-terrestrial networks, we will outline the timing alignment verification for communication using PUR in terrestrial networks, in accordance with 3GPP TS36.331, Section 5.3.3.19.

[0067] The UE shall consider the timing alignment value for transmission using PUR to be valid if the following conditions are met: 1> Either pur-TimeAlignmentTimer is not configured, or pur-TimeAlignmentTimer is operating as confirmed by the lower layer, and 1> Either pur-RSRP-ChangeThreshold (pur-NRSRP-ChangeThreshold in NB-IoT) is not set, or one of the following conditions is met. 2> Compared to the stored serving cell reference (N)RSRP value, the serving cell (N)RSRP has not increased by more than increaseThresh, and 2> The serving cell (N)RSRP is not greater than the declineThresh value compared to the stored serving cell reference (N)RSRP value.

[0068] Therefore, in terrestrial networks, before transmission using PUR, the UE3 checks that it has a valid timing alignment (or timing advance) value (i.e., the associated pur-TimeAlignmentTimer is not configured or has not expired), and (if such a threshold is configured) certifies that the fluctuation in the current cell's reference signal received power does not exceed the configured threshold in either direction.

[0069] Looking at the non-terrestrial portion of Network 1, it becomes clear that satellite coverage can be discontinuous, especially for IoT devices located in remote areas. If UE3 (IoT device) is serviced by satellite 5, cell coverage lasts for Δt within a period T, and both Δt and T can vary. For example, if UE3 is serviced by a single satellite (LEO at an altitude of 600km), the interval T can vary between 9 and 13.3 hours, and the coverage time Δt can vary from 1 to 4 minutes. In the example shown in Figure 5, satellite coverage is available in windows labeled A, B, C, and D (each representing a different period T). The windows may have different durations and may be unevenly spaced. In some areas, satellite coverage may be unavailable at all (for example, if there are no satellites deployed to service that area and / or that particular UE3). This means that after the applicable coverage time Δt (or after UE3 moves to an area where coverage is unavailable), the variation in UE3's reference signal received power exceeds the configured threshold, and the timing alignment is no longer valid for that cell. Furthermore, rapid relative movement between UE3 and satellite 6 also results in significant variation in reference signal received power, which also renders the timing alignment no longer valid for that cell.

[0070] However, there are benefits to using PUR even for NGSO-based cells, particularly for IoT devices and similar UE3s. The median flyover lasts approximately 220 seconds, with 90% of flyovers lasting longer than 110 seconds. The link budget weakens at low elevation angles. Therefore, UE3s need to complete their uplink transmissions within a limited coverage time. This can be problematic, and using the usual (permission-based) scheduling method can also increase signaling-related power consumption. By using PUR, UE3s can perform uplink transmissions in an RRC idle state using an active PUR without having to perform random access procedures to obtain uplink permission. By reducing the time spent on uplink transmission procedures, UE power consumption and network workload can also be reduced. Since power consumption is a critical issue for IoT devices, reduced power consumption can potentially extend the lifespan of these devices.

[0071] This disclosure discusses various ways in which UE3 can be configured to use a PUR composed of a given cell in another cell, even within a cell with discontinuous coverage that lasts for a relatively short period of time (NTN cell), in contrast to the cell-specific PUR currently proposed in the 3GPP specification (Release 16).

[0072] Figure 6 schematically illustrates an exemplary scenario in which satellite 5 covers UE3 between time t1 and time t2 via an associated serving cell. Substantially, the cell's coverage time Δt is given by t2-t1. Figure 7 is substantially the same scenario as shown in Figure 6. In this case, the first satellite 5A covers UE3 between time t1 and time t2 via its cell A, which may be configured with associated PUR configuration A (when the associated RRC connection is released or reconfigured). UE3 (e.g., an IoT device) may not have frequent uplink data. Therefore, it may not use the PUR configured by cell A within cell A. Now looking at Figure 8, the same satellite 5A (or a different satellite 5B) covers UE3 between time t3 and time t4 via cell B, which may continue to apply associated PUR configuration A or apply a new PUR configuration B and transmit uplink data accordingly. For a specific area, such as a geographical area, the network may configure the "same" resources for cells covering that area at different times. Therefore, PUR / PUR configurations can be reused between cells. Beneficially, UE3 can also save power by continuing to use the old PUR configuration in a new cell, or by adapting the old PUR configuration to a new cell.

[0073] <Solution 1> In this solution, the PUR configuration is associated with multiple cells (identified, for example, by a cell list).

[0074] For example, an information element for configuring the PUR (such as "pur-Config") or any other appropriate information element may be used to identify one or more cells (NTN cells) to which the PUR configuration can be applied by the UE3. It will be understood that the information element may be included in a properly formatted RRCConnectionRelease message, etc. The RRCConnectionRelease message is used in 3GPP systems to command the release of an RRC connection (direction: network to UE). Some relevant details of the RRCConnectionRelease message, including the "pur-Config-r16" information element (from Release 16) for setting up or releasing the PUR configuration, are shown below. It will be understood that a similar effect can be achieved using a properly formatted RRC reconstruction message.

[0075] With existing technologies, if UE3 changes the cell it is camped on, the configured PUR becomes invalid, and UE3 must perform a random access procedure before sending any uplink data.

[0076] In the NTN scenario (for example, in the NGSO scenario), the coverage time for each cell is limited, so UE3 may change cells due to satellite movement rather than UE mobility. The network may configure the same resources for the same area via different satellites at different times. In this case, PUR configured in one cell may be applicable to other cells in the same area.

[0077] In this example (referred to as "Solution 1"), base station 6 (using its communication control module 63) notifies UE3 of the cells that can use the configured PUR (in the form of a cell list, etc.). Therefore, when performing uplink transmission, UE3 (using its communication control module 43) checks the PUR by checking whether the UE's current cell is included in the cell list. In this case, the current cell refers to the cell where UE3 is idle and camped.

[0078] For example, base station 6 may send the PUR configuration to UE3 via the RRC connection release or reconfiguration message described above. The cell list may be contained within the "pur-Config" information element (e.g., in the release 17 version) or any other appropriate information element. The cell list may also be contained in a different message, for example, in a System Information Block (SIB), if appropriate. At least some of the cells in the cell list may be replacement cells for cells that have configured the PUR, i.e., cells that cover the same area at different times. The cell list may include the cell's physical cell ID (PCI), cell global ID (CGI), carrier frequency, etc. (e.g., in one or more associated information elements). In some cases, the cell list may contain only one cell (at least initially, or after the removal of one or more cells). Multiple cells (or cell lists) may be provided by adding cells to an existing set of cells. A set of cells may contain one cell (e.g., initially). Cells may be added one at a time or in groups. Removing one or more cells from a cell list can be achieved in a similar manner to adding cells. A replacement cell may remove the cell it replaces from the cell list. Alternatively, the replacement cell may be added to the cell list.

[0079] In summary, the network (base station 6) configures UE3 to communicate over the non-terrestrial network portion using pre-configured uplink resources. The network does this by sending appropriate configuration information that identifies the pre-configured uplink resources for UE3 to use in the RRC idle state, and also by sending information that identifies the cells to which the configuration information is applicable (e.g., by a list of cells). The configuration information may be sent to UE3 in a properly formatted message to release the RRC connection (such as the RRCConnectionRelease message described above) or an RRC reconfiguration message. The cell list may also be sent in the same message or using a different message (e.g., via a system information block).

[0080] UE3 stores the PUR configuration (in its memory 39) and applies the PUR configuration to any cell in the cell list, provided that any other associated conditions are met. At some point, UE3 performs cell reselection and camps on to a new cell. If the new cell's information, i.e., PCI, GCI, etc., is included in the cell list associated with the PUR configuration, UE3 considers the configured PUR to be available for use in this new cell. For example, if the PUR was configured by cell A (Figure 7) and cell B is included in the cell list, then the PUR can also be used in cell B (Figure 8).

[0081] It will be understood that the base stations 6 may be configured to cooperate with each other (via the network interface 55) to exchange information related to their PUR configurations and associated cell lists. One or more satellites 5 covering a specific area at different times may be serviced by different base stations 6, i.e., satellite A and satellite B connect to base stations A and B, respectively. Alternatively, the same satellite 5 may connect to different base stations 6 (gateways) at different times and service the same area through different cells. The PUR configuration, including the cell list, is exchanged between the base stations 6. Therefore, when generating the cell list, the base stations 6 can configure the appropriate resources to support a PUR composed of multiple cells.

[0082] <Solution 2> In this solution, UE3 is configured to use its PUR configuration from the previous cell within a new serving cell that is determined to be either identical to or a replacement for the previous cell. In this case, it is not necessary to provide UE3 with a list of cells in advance, as UE3 may be able to determine whether the PUR configuration is available in the new cell.

[0083] Referring again to Figures 7 and 8, for a particular area, the coverage of cell A and cell B may be provided by satellites A and B at different times, respectively. Alternatively, the same satellite may serve cell A and cell B at different times. However, it will be understood that some resources and configurations may be the same for both cell A and cell B.

[0084] For example, cell B may be named as a replacement cell for cell A. In other words, the network (base station 6) may provide an explicit instruction that cell B replaces cell A. In this case, UE3 can consider the two cells as "identical" cells and continue to apply some of the configuration from cell A (in this case, PUR) to cell B as well.

[0085] To determine whether the configuration provided by the previous serving cell is available for use in the new cell, the following actions may be performed:

[0086] Base station 6 indicates whether the new serving cell (cell B) is the "identical" / alternative cell to the previous serving cell (cell A). One option is for base station 6 to explicitly indicate whether the new serving cell (cell B) is the "identical" one to the previous serving cell (cell A). The indication can be provided in various forms and by various means. For example, base station 6 may indicate whether the cell can be considered "identical" to the previous serving cell (cell A), or whether a previously configured PUR can be used in the new cell (cell B), etc.

[0087] Alternatively, base station 6 implicitly indicates whether the new serving cell (cell B) is the "identical" / alternative cell to the previous serving cell (cell A). For example, the base station may place the same carrier frequency and the same cell parameters in cells A and B. UE3 stores information about the previous serving cell A (e.g., carrier frequency, PCI, Master Information Block (MIB), SIB, etc.). In other words, UE3 holds in its memory 39 the parameters associated with the cell configured for UE3 by the PUR. UE3 may maintain this information for at least a predetermined period, or until the PUR is released by the network, or until UE3 moves to an area where no alternative cells are available. When UE3 begins camping on to the new cell (cell B), UE3 monitors / acquires the PSS, SSS, MIB, SIB, etc. of cell B (which is serviced by satellite A or satellite B).

[0088] When a UE determines whether cell A and cell B are the same (or equivalent) cells: If cell A and cell B are the "same" cells, the PUR configured in cell A is still valid in cell B and can be used for uplink transmission. For example, UE3 may be configured to consider two cells the same / identical if one or more of the following parameters are the same: PCI, CGI, carrier frequency, bandwidth, system information value tag, cell identification information, etc. For example, system information (e.g., MIB) may include a suitable indication that the system information remains unchanged (the value of the systemInfoUnchanged-BR field in the MIB may be set to "TRUE"). In this case, it is not necessary to send the above parameters in the new cell, or UE3 does not need to obtain the above parameters to determine that the new cell and the cell in which the PUR was originally configured are the same.

[0089] In summary, the network (base station 6) configures UE3 to communicate over the non-terrestrial network portion using pre-configured uplink resources. The network does this by sending appropriate configuration information that identifies the pre-configured uplink resources for UE3 to use in the current cell (the current cell may also be called the first cell or old cell) while RRC idle. The configuration information may be sent to UE3 in a properly formatted message to release the RRC connection (e.g., an RRCConnectionRelease message) or an RRC reconfiguration message. The network (base station 6) also provides appropriate instructions (explicit or implicit) that enable UE3 to continue using its PUR configuration in a new serving cell (within substantially the same geographic area). If UE3 receives such explicit or implicit instructions, for example via MIB / SIB, UE3 will assume, based on these instructions, that the PUR is applicable to the new cell.

[0090] Beneficially, UE3 can determine whether to continue applying configuration information to the new (second) cell when the new cell replaces an old cell in the UE, or when the new cell corresponds to an old cell (when the UE is outside the coverage of the old cell). For example, the network / base station 6 may provide appropriate instructions (e.g., via a system information block) to inform UE3 that the new cell is identical to or corresponds to an old cell. Alternatively, UE3 may determine that the new cell is identical to or corresponds to an old cell based on implicit instructions (by evaluating one or more cell-specific parameters and determining that the relevant parameters are the same in both the old and new cells).

[0091] <Solution 3> In this solution, PUR is effective as long as UE3 is covered by the satellite (regardless of which cell). It will be understood that solution 3 can be combined with solution 1 or solution 2 (at least some of its features).

[0092] This solution relies on the following characteristics that can be adapted for this purpose. (Currently proposed for quasi-Earth-fixed satellites such as LEOs with steerable beams) Providing information on the start time of (arriving) satellite coverage and the end time of serving satellite coverage, and Satellite ephemeris (orbital information) parameters for predicting coverage discontinuities (in conjunction with any other relevant information such as beam information, elevation angle, and reference position).

[0093] Beneficial in the case of discontinuous coverage (in non-terrestrial cells), base station 6 notifies UE3 of the relevant satellite information, and UE3 is permitted to use its configured PUR while satellite coverage is available. In such cases, it will be understood that UE3 may be serviced by one or a few satellites 5. Coverage may be discontinuous (e.g., characterized by a period T and a coverage window Δt, as described above) due to relative movement between UE3 and (one or more) satellites 5 in an NGSO scenario. If UE3 is outside the coverage of any satellite, UE3 (e.g., an IoT device) may be configured to remain in this situation (i.e., not attempt to connect to the network via a terrestrial cell), especially if UE3 does not have frequent data to transmit.

[0094] Base station 6 may transmit appropriate support information to UE3. For example, the support information may include satellite information (e.g., coverage start and end times, satellite ephemeris, etc.) and timing advance-related parameters. Alternatively, “satellite information” and appropriate “non-terrestrial node information” may be provided, and it will be understood that this may also apply to other types of non-terrestrial nodes such as HAPS and UAVs.

[0095] Using the received support information, the UE3 can predict satellite or cell coverage time and / or calculate applicable timing advance values. The UE3 may be configured to wake up only when coverage is available, which would improve the UE's battery life / power consumption.

[0096] UE3 maintains its PUR configuration when it is outside of coverage. Whenever UE is back in coverage, it is allowed to use the configured PUR. Unless UE3 is configured with a list of cells to which the PUR can be applied (for example, as described in Solution 1), UE3 may use the configured PUR regardless of which non-ground cells it camps on.

[0097] Satellite information (or non-terrestrial node information) is associated with a PUR configuration. Different PUR configurations may be provided for different associated satellite information, allowing the UE3 to benefit from different configurations depending on which satellite (or time window) is used by the UE3. For example, a first set of time windows may be provided with the first PUR configuration (via appropriate support information) during off-peak hours, and a second set of time windows may be provided with the second PUR configuration (or without a PUR configuration) via appropriate support information to control (or prevent) uplink transmission during relative busy periods. In the case of discontinuous coverage, the UE3 may also be serviced sequentially by different satellites. In this case, the UE3 may be configured to use its PUR only if the coverage is provided by one satellite / (one or more) satellites or cells associated with the PUR configuration (i.e., the PUR is unavailable if the coverage is provided by other satellites or cells).

[0098] In legacy PUR configurations, there is an information element (pur-ImplicitReleaseAfter) that controls the release of a PUR configuration. Specifically, based on this information element, UE3 releases its PUR configuration and / or considers it invalid if UE3 does not use a PUR opportunity for a consecutive number of times given by the value of the information element. To avoid UE3 releasing a PUR configuration due to discontinuous coverage, this system counts PUR opportunities only when UE3 is within coverage (or within a predefined window). This approach is schematically illustrated in Figure 9, where black boxes represent PUR opportunities while UE3 is within coverage (these opportunities are considered when counting missed PUR opportunities), and white boxes represent PUR opportunities while UE3 is outside coverage (these opportunities are not considered when counting missed PUR opportunities). When UE3 is outside of coverage or re-enters coverage, the number of opportunities counted by UE3 may be reset to "0". Alternatively, the network can configure UE3 not to count PUR opportunities missed in non-terrestrial cells (for example, by omitting the pur-ImplicitReleaseAfter information element from the relevant PUR configuration, or by setting the pur-ImplicitReleaseAfter information element to "0", "Max", "Off", or any other appropriate value indicating that the count is off).

[0099] In summary, the network (base station 6) configures UE3 to communicate over the non-terrestrial network portion using pre-configured uplink resources. The network does this by transmitting appropriate configuration information in at least one non-terrestrial cell during RRC idle state, identifying the pre-configured uplink resources for UE3 to use. The network also transmits coverage information (coverage start time, end time, etc.) provided over at least one non-terrestrial cell. Based on the coverage information, UE3 applies the configuration information.

[0100] <Solution 4> In this solution, PUR is effective within the configured area, as schematically shown in Figures 10 and 11.

[0101] According to existing technology, a UE considers its PUR invalid when fluctuations in the reference signal received power exceed a configured threshold (if configured). These fluctuations may indicate positional fluctuations that result in the termination of timing alignment and cause radio link fluctuations. However, in the NTN scenario, fluctuations in the reference signal received power may not be related to the mobility of UE3, as they are more likely to be caused by the movement of satellite 5 providing service to UE3.

[0102] UE3 may have GNSS capabilities (or similar capabilities) and may include a suitable positioning module 45. Such UE3 is typically aware of its geographical location and can calculate the required timing alignment (timing advance) based on satellite information and any timing alignment / timing advance related parameters provided by the network. Therefore, in non-terrestrial networks, it is not necessary to limit the position variation of UE3 using RSRP thresholds. It will be understood that some UEs, particularly IoT UEs, may be able to acquire their GNSS position only when RRC idle or when there is no other operation due to their relatively simple components. Nevertheless, once acquired, the position information is valid for a period of time before it needs to be acquired again.

[0103] Figure 10 shows a first approach to limiting the effectiveness of PUR to an appropriate area. Essentially, PUR is effective when UE3 is within this (pre-configured or predetermined) area, and ineffective when UE3 is outside this area. In this case, base station 6 configures a threshold that limits the maximum allowable variation in the UE's position. The threshold may be applied to an appropriate reference position, such as the UE's position when the RRC connection is released or the first subsequent position acquired in an RRC idle state. By comparing the UE's current position to a stored reference position, UE3 can determine the position variation (by calculating the distance from the current position to the reference position). If the variation exceeds the associated threshold, the timing alignment and / or configured PUR are considered ineffective.

[0104] Figure 11 illustrates a second approach to limiting the effectiveness of PUR to a specific area. In this case, base station 6 implicitly or explicitly indicates the cell coverage area associated with the PUR configuration to UE3. Base station 6 may also indicate the cell coverage area by providing information such as beam footprint size and geographical location of cell centers, from which UE3 can determine the area to be serviced by the satellite. In this case, the satellite position (if known from ephemeris data, etc.) can be used as a reference point along with beam information to determine the area where PUR is effective.

[0105] In summary, the network (base station 6) configures the UE3 to communicate over the non-terrestrial network portion using pre-configured uplink resources. The network does this by sending appropriate configuration information to identify the pre-configured uplink resources for the UE3 to use in at least one non-terrestrial cell while the RRC is idle. The configuration information may be sent to the UE3 in a properly formatted message to release the RRC connection (e.g., an RRCConnectionRelease message) or an RRC reconfiguration message. The network (base station 6) also provides information to identify areas to which the configuration information is applicable, enabling the UE3 to continue using its PUR configuration in a new serving cell (within substantially the same geographical area).

[0106] <Solution 5> In this solution, UE3 is configured to determine whether its PUR configuration is valid by starting and stopping the associated timers (and, if appropriate, ignoring the timers). In effect, UE3 is configured to handle timers associated with the PUR differently depending on whether UE3 is serviced by a ground cell or a non-ground cell.

[0107] In terrestrial networks, before transmitting using PUR, UE3 checks whether the associated timing advance value is still valid (i.e., whether the so-called pur-TimeAlignmentTimer has expired) and (if configured for UE3) whether the fluctuation in the current cell's reference signal received power exceeds a configured threshold.

[0108] However, in non-terrestrial networks, such timers may not be provided at all, or they may be ignored by the UE3. The UE3 may be able to autonomously determine the appropriate timing advance (from satellite information / ephemeris data, UE position, and other supporting information), so the UE3 does not necessarily need to rely on timers in non-terrestrial networks.

[0109] If timers are also configured for the non-terrestrial network portion, UE3 may be configured not to start (or ignore) the timers when using non-terrestrial network services or when camping on to a non-terrestrial network cell. Even if UE3 starts the timers, the timer's expiration does not affect PUR confirmation for the non-terrestrial network.

[0110] Another approach is schematically shown in Figure 12. In this case, UE3 stops or pauses the timing alignment timer (e.g., pur-TimeAlignmentTimer) when leaving the serving cell and restarts or continues the timer when camping on to a new serving cell (different from the PUR configuration cell). In other words, the timer only operates while UE3 is within coverage of the non-terrestrial network (satellite coverage is available). Figure 12 shows a scenario where the timer continues to operate when UE3 begins camping on to a new serving cell. On the other hand, Figure 13 shows the possibility of restarting the timer (using an initial value) rather than continuing it.

[0111] In effect, UE3 can be configured to stop the pur-TimeAlignmentTimer when changing serving cells, or to consider it expired, and to continue or restart the timer when camping on to the new cell. This solution may be composed of any other solution, if appropriate.

[0112] The duration of the associated timer in one or more new serving cells may be configured by the initial PUR configuration (via one or more associated information elements) and / or provided in the new serving cell (e.g., in the system information). Thus, different durations of the PUR configuration may be applied in different cells, or different durations may be associated with one or more different cells by indicating the association.

[0113] In an alternative approach, UE3 ignores the pur-TimeAlignmentTimer in (one or more) new serving cells. Effectively, UE3 may be configured to stop the timer or consider it expired when it leaves a cell where the PUR is configured. In this case, the timer expiration does not invalidate the PUR. In this case, UE3 may be configured to wait until the same cell coverage becomes available before continuing to apply the PUR configuration. This approach may be useful when different UEs (or groups of UEs) are associated with different satellites or cells and when transmitting delay-tolerant data. It will be understood that this approach can be combined with the approach described above, with reference to Figure 12.

[0114] Figure 13 schematically illustrates yet another approach to handling timers associated with PUR in non-terrestrial cells. In this case, UE3 stops the timer (pur-TimeAlignmentTimer) associated with the end of coverage of the serving satellite, thereby disabling the PUR configuration. In contrast, in terrestrial cells or any other cells with continuous coverage, the PUR configuration is disabled when the associated pur-TimeAlignmentTimer expires. In effect, in this case, UE3 controls the effectiveness of the Timing Advance Value / PUR configuration based on whether UE3 is in a non-terrestrial cell (to which the Timing Advance Value / PUR configuration applies).

[0115] When UE3 begins camping on to a new serving cell at the next start time of (arriving) satellite coverage, the UE's behavior may be the same as any of the other approaches described above. For example, UE3 may restart the timer (depending on which satellite / non-terrestrial node will service the new serving cell).

[0116] In summary, when satellite coverage ends or becomes unavailable, UE3 stops its associated PUR timer (pur-TimeAlignmentTimer), and when satellite coverage becomes available, it starts (restarts) the PUR timer each time it begins camping on to a new cell (including the initial cell when UE3 releases its RRC connection). In other words, while UE3 is outside of satellite (NTN cell) coverage, the associated timer is not operating. Therefore, UE3 does not need to count PUR opportunities while the timer is not operating (see Figure 9), and UE3 may be able to enter a power-saving or low-power mode sooner.

[0117] <Examples of corrections and alternatives> Detailed embodiments have now been described. As those skilled in the art will understand, several modifications and substitutions can be made to the embodiments described above while still benefiting from the disclosure embodied in the above embodiments. Some of these substitutions and modifications are described here only as examples.

[0118] Base stations for 5G / NR communication systems are generally called new radio base stations ("NR-BS") or "gNBs," but it will be understood that they may also be referred to using the term "eNB" (or 5G / NR eNB), which is more typically associated with Long-Term Evolution (LTE) base stations (commonly also called "4G" base stations). The term base station may refer to any of the following nodes as defined in 3GPP Technical Specifications 38.300 (V16.8.0) and 37.340 (V16.8.0):

[0119] A node that provides protocol termination for the NR user plane and control plane toward the gNB:UE and is connected to the 5G Core Network (5GC) via the NG interface.

[0120] ng-eNB: A node that provides protocol termination for the E-UTRA (Evolved Universal Terrestrial Radio Access) user plane and control plane toward the UE, and is connected to 5GC via the NG interface.

[0121] A node that provides protocol termination for the NR user plane and control plane toward En-gNB:UE, and functions as a secondary node in EN-DC (E-UTRA-NR Dual Connectivity).

[0122] NG-RAN node: Either gNB or ng-eNB.

[0123] It will be understood that the above embodiments may be applicable to both 5G new wireless systems and LTE systems (E-UTRAN). Base stations (gateways) that support the E-UTRAN / 4G protocol may be called "eNBs," and base stations that support the NextGeneration / 5G protocol may be called "gNBs." It will be understood that some base stations may be configured to support both 4G and 5G protocols, and / or any other 3GPP or non-3GPP communication protocols.

[0124] Table 1 Types of Satellites and UAS Platforms [Table 1]

[0125] It will be understood that there are various architectural options for implementing NTN in 5G / NR systems, some of which are schematically shown in Figure 14. The first option illustrated is an NTN that serves the UE and features a satellite / air-based access network with a vent-pipe type payload and a ground-based gNB (satellite hub or gateway level). The second option is an NTN that serves the UE and features a satellite / air-based access network equipped with a gNB. The third option is an NTN that serves relay nodes and features a satellite / air-based access network with a vent-pipe type payload. The fourth option is an NTN that serves relay nodes and features a satellite / air-based access network with a gNB. It will be understood that other architectural options, such as combinations of several of the above options, may also be used. Alternatively, the relay nodes may have satellite / UAS. Similar architectural options may be used in 4G / E-UTRA systems, but it will be understood that an eNB is used instead of a gNB and an EPC is used instead of an NGC.

[0126] For ease of understanding, the above description assumes that the UE, NTN node (satellite / UAS platform), and access network node (base station) have several separate modules (such as a communications control module). These modules may be provided in this way in certain applications, for example, where an existing system is modified to implement the present disclosure. However, in other applications, such as systems designed from the outset with the features of the present invention in mind, these modules may be integrated into the overall operating system or code, and therefore may not be identifiable as separate entities. These modules may be implemented in software, hardware, firmware, or a combination thereof.

[0127] Each control unit may include, for example (but not limited to), one or more hardware-implemented computer processors, microprocessors, central processing units (CPUs), arithmetic logic units (ALUs), input / output (IO) circuits, internal memory / cache (programs and / or data), processing registers, communication buses (e.g., control buses, data buses and / or address buses), direct memory access (DMA) functions, hardware or software-implemented counters, pointers and / or timers, and any other suitable form of processing circuitry.

[0128] In the embodiments described above, several software modules were explained. As those skilled in the art will understand, the software modules may be provided in compiled or uncompiled form and supplied to the UE, NTN nodes, and access network nodes (base stations) via a computer network or as signals on a recording medium. Furthermore, the functions performed by some or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred because it facilitates the updating of the UE, NTN nodes, and access network nodes (base stations) to update their functions.

[0129] The above embodiments are also applicable to "non-mobile" or generally fixed user devices.

[0130] The first method implemented by the UE may include receiving configuration information in a message to release the RRC connection or a message to reconfigure the RRC.

[0131] The first method implemented by the UE may further include transmitting data using pre-configured uplink resources in cells that are contained within multiple cells.

[0132] Information identifying multiple cells may include, for each cell, at least one of the following: physical cell ID (PCI), cell global ID (CGI), and carrier frequency.

[0133] Information identifying multiple cells may include a list of cells or an area configuration. The area configuration may be defined or received separately from the configuration information and may cover multiple cells.

[0134] Pre-configured uplink resources may be associated with a predetermined geographical area.

[0135] A second method implemented by the UE may further include transmitting data using pre-configured uplink resources in a second cell based on configuration information.

[0136] A second method implemented by the UE may further include determining that the second cell corresponds to the first cell based on instructions received from a base station providing service to the first cell or from a base station providing service to the second cell.

[0137] The instructions may indicate that the second cell is substantially identical to the first cell. Alternatively, the instructions may indicate that a pre-configured uplink resource is applicable to the second cell.

[0138] A second method implemented by the UE may further include receiving instructions via a master information block or a system information block.

[0139] The second method implemented by the UE may further include determining that the second cell corresponds to the first cell based on at least one of the following: an information element indicating that the system information has not been changed; physical cell identification information (PCI) associated with the second cell; cell global ID (CGI); carrier frequency; bandwidth; system information value tag; cell identification information; primary synchronization signal (PSS); secondary synchronization signal (SSS); master information block (MIB); and system information block (SIB).

[0140] The UE's receiving of coverage information may include receiving at least one of the following: ephemeris data for at least one non-terrestrial cell, information identifying the coverage start time associated with at least one non-terrestrial cell, information identifying the coverage end time associated with at least one non-terrestrial cell, and timing advance parameters associated with at least one non-terrestrial cell.

[0141] A third method implemented by the UE may further include transmitting data using pre-configured uplink resources based on configuration information.

[0142] A third method implemented by the UE may further include controlling the UE's wake-sleep behavior based on coverage information, such that the UE wakes up and applies configuration information when it is determined that the UE is within coverage.

[0143] A third method implemented by the UE may further include applying configuration information when the UE camps on to a cell belonging to at least one non-ground cell based on coverage information, and maintaining configuration information when the UE is outside of coverage based on coverage information.

[0144] A third method implemented by the UE may further include receiving information that identifies at least one non-terrestrial node to which configuration information is applicable.

[0145] A third method implemented by the UE is to receive information identifying the number of opportunities the UE is allowed to miss a pre-configured uplink resource before releasing configuration information identifying the pre-configured uplink resource, the number of opportunities may further include identifying the number of opportunities within one predetermined period in which the UE is within the coverage of at least one non-terrestrial cell.

[0146] A fourth method implemented by the UE may further include transmitting data using pre-configured uplink resources based on information for identifying the area.

[0147] Information for identifying an area may include information indicating the beam footprint size. Information for identifying an area may include a threshold for variation in the UE's position.

[0148] While the UE is within the area, applying configuration information may include determining the difference between the reference location and the UE's current location, and applying the configuration information if the difference is less than or equal to a threshold. The reference location may be the UE's location when it enters the RRC idle state, in response to receiving a message containing configuration information or a message containing location acquired in the RRC idle state after receiving a message containing configuration information.

[0149] Controlling the effectiveness of timing advance values ​​may include ignoring the associated effectiveness timer when the UE is using non-terrestrial services or when the UE is camped on a non-terrestrial cell.

[0150] Controlling the validity of the timing advance value may include starting the associated validity timer and treating the timing advance value as valid when the validity timer expires, if the UE is using non-terrestrial services or camp-on to a non-terrestrial cell.

[0151] Controlling the effectiveness of the timing advance value may include stopping the associated effectiveness timer when the serving cell is changed from the cell where the configuration information was received to a different cell.

[0152] Controlling the effectiveness of the timing advance value may include restarting the associated effectiveness timer when the UE chooses to camp on to a new non-ground cell.

[0153] A fifth method implemented by the UE may further include receiving information identifying the respective values ​​of the associated validity timers for each of at least one non-terrestrial cell.

[0154] Controlling the effectiveness of timing advance values ​​may include not applying the effectiveness timer associated with different cells.

[0155] A fifth method implemented by the UE may further include receiving information identifying a coverage start time associated with at least one non-terrestrial node serving at least one non-terrestrial cell, and starting an effectiveness timer at the coverage start time to enable a timing advance value in at least one non-terrestrial cell.

[0156] A fifth method implemented by the UE may further include receiving information identifying the coverage end time associated with at least one non-terrestrial node that provides service to at least one non-terrestrial cell, and stopping the validity timer associated with the coverage end time to disable the timing advance value in at least one non-terrestrial cell.

[0157] Various other modifications are obvious to those skilled in the art and will not be described in further detail here.

[0158] While this disclosure has been described with reference to exemplary embodiments, it is not limited to those described above.

[0159] Various modifications that a person skilled in the art can understand may be made to the structure and details of this disclosure within the scope of this disclosure.

[0160] Programs can be stored and provided to computer devices using any type of non-temporary computer-readable medium. Non-temporary computer-readable medium includes any type of tangible storage medium. Examples of non-temporary computer-readable medium include magnetic storage media (e.g., floppy disks, magnetic tapes, hard disk drives, etc.), magneto-optical storage media (e.g., magneto-optical disks), CD-ROMs (read-only memory), CD-Rs, CD-R / Ws, and semiconductor memory (e.g., mask ROMs, PROMs (programmable ROMs), EPROMs (erasable PROMs), flash ROMs, RAMs (random access memory), etc.). Programs may also be provided to computer devices using any type of temporary computer-readable medium. Examples of temporary computer-readable medium include electrical signals, optical signals, and electromagnetic waves. Temporary computer-readable medium can be provided to computer devices via wired communication lines such as electric wires and optical fibers, or via wireless communication lines.

[0161] For example, all or part of the exemplary embodiments disclosed above may be described as follows, but are not limited thereto. (Note 1) A method implemented by user equipment (UE) for communication over a non-terrestrial network, wherein the method is Receiving configuration information that identifies pre-configured uplink resources for use by the UE in the Wireless Resource Control (RRC) idle state, Authenticating whether the aforementioned configuration information is still valid, In accordance with the authentication, it is determined whether to transmit data using the pre-configured uplink resources. Methods that include... (Note 2) Receiving information indicating whether the aforementioned configuration information is valid. It further includes, The aforementioned authentication is performed using the aforementioned information. The method described in Appendix 1. (Note 3) The aforementioned information includes cell information that identifies a plurality of cells in which the configuration information is valid, The aforementioned authentication is performed by using the cell information. The method described in Appendix 2. (Note 4) The aforementioned information includes cell information that identifies multiple cells that are identical to or substitute for the first cell corresponding to the configuration information, The authentication is performed by using the cell information when the UE is outside the coverage of the first cell and within the coverage of a second cell which is included in the plurality of cells indicated by the cell information. The method described in Appendix 2. (Note 5) The aforementioned cell information is, for each cell, Physical cell ID (PCI), Cell Global ID (CGI), Carrier frequency including at least one of the following: The method described in Appendix 3 or 4. (Note 6) The aforementioned cell information includes a list or area configuration of cells. The method described in any one of the appendices 3 to 5. (Note 7) The aforementioned area configuration is defined or received separately from the aforementioned configuration information and covers multiple cells. The method described in Appendix 6. (Note 8) Information elements indicating that system information has not been changed. Physical cell identification information (PCI), Cell Global ID (CGI), Carrier frequency, bandwidth System information value tag, Cell identification information, Primary synchronization signal (PSS), Secondary synchronous signal (SSS), Master Information Block (MIB), and System Information Block (SIB) associated with the second cell Determining that the second cell corresponds to the first cell based on at least one of the following: This also includes, The method described in Appendix 4. (Note 9) The information includes coverage information relating to coverage provided through at least one non-terrestrial cell operated by the non-terrestrial network, The aforementioned authentication is performed by using the aforementioned coverage information. The method described in Appendix 2. (Note 10) The aforementioned coverage information is, Ephemeris data relating to at least one non-terrestrial cell, Information identifying the coverage start time associated with the at least one non-terrestrial cell, Information identifying the coverage end time associated with the at least one non-terrestrial cell, and Timing advance parameters associated with the at least one non-ground cell including at least one of the following: The method described in Appendix 9. (Note 11) The wake-sleep behavior of the UE is controlled based on the information relating to the coverage, such that the UE wakes up and applies the configuration information when it is determined that the UE is within the coverage. This also includes, The method described in Appendix 9 or 10. (Note 12) Applying the configuration information when the UE camps on to a cell belonging to at least one non-terrestrial cell based on the coverage information, Based on the coverage information, maintain the configuration information when the UE is outside the coverage area. This also includes, The method described in any one of the appendices 9 to 11. (Note 13) Receiving information that identifies at least one non-terrestrial node to which the above configuration information is applicable. This also includes, The method described in any one of the appendices 9 to 12. (Note 14) Receiving information that identifies the number of times the UE is allowed to miss the pre-configured uplink resource before releasing the configuration information, The number of opportunities identifies the number of opportunities within at least one predetermined period in which the UE is within the coverage of the at least one non-terrestrial cell. This also includes, The method described in any one of the appendices 9 to 13. (Note 15) The aforementioned information includes location information for identifying the area in which the configuration information is valid. The aforementioned authentication is performed by using the aforementioned location information. The method described in Appendix 2. (Note 16) The aforementioned location information indicates a predetermined geographical area. The method described in Appendix 15. (Note 17) The aforementioned position information includes information indicating the beam footprint size. The method described in Appendix 15 or 16. (Note 18) The position information includes a threshold for variation in the position of the UE. The method described in any one of the appendices 15 to 17. (Note 19) Determine the difference between the reference position and the current position of the aforementioned UE. It further includes, If the difference is less than or equal to the threshold, the configuration information is authenticated as valid. The method described in Appendix 18. (Note 20) The aforementioned reference position is the position of the UE when it enters the RRC idle state in response to receiving a message containing the configuration information or a message containing the configuration information or position acquired in the RRC idle state after receiving a message containing the configuration information. The method described in Appendix 19. (Note 21) The information includes control information for controlling a timer for transmission using the pre-configured uplink resources, The authentication is performed by using the timer controlled by the control information. The method described in Appendix 2. (Note 22) The effectiveness of the timing advance value corresponding to the timer is controlled based on whether the UE is located in at least one non-terrestrial cell operated by the non-terrestrial network. It further includes, The authentication is performed based on the control of the effectiveness of the timing advance value. The method described in Appendix 21. (Note 23) Controlling the effectiveness of the timing advance value is This includes ignoring the timer when the UE is using a non-terrestrial service or when the UE is camped on to one of the at least one non-terrestrial cell, The method described in Appendix 22. (Note 24) Controlling the effectiveness of the timing advance value is Starting the aforementioned timer, When the UE is using a non-terrestrial service, or when the UE is camped on one of the at least one non-terrestrial cells, the timing advance value is made valid when the timer expires. including, The method described in Appendix 22. (Note 25) Controlling the effectiveness of the timing advance value includes stopping the timer when the serving cell is changed from the cell from which the configuration information was received to a different cell. The method described in Appendix 22. (Note 26) Controlling the effectiveness of the timing advance value includes restarting the timer when the UE chooses to camp on to a new non-ground cell. The method described in Appendix 22 or 25. (Note 27) The further includes receiving information identifying the respective values ​​of the timers for each of the at least one non-terrestrial cell, The method described in any one of the appendices 23 to 26. (Note 28) Controlling the effectiveness of the timing advance value includes not applying the timer associated with the different cell. The method described in Appendix 25. (Note 29) Receiving information identifying the coverage start time associated with at least one non-terrestrial node that provides services to the at least one non-terrestrial cell, The timer is started at the coverage start time to enable the timing advance value in at least one non-ground cell, This also includes, The method described in any one of the appendices 22 to 28. (Note 30) Receiving information identifying the coverage end time associated with the at least one non-terrestrial node that provides services to the at least one non-terrestrial cell, The timer is stopped at the coverage end time, and the timing advance value is disabled in at least one non-ground cell. This also includes, The method described in any one of the appendices 22 to 29. (Note 31) The aforementioned configuration information is included in the message for releasing the RRC connection or the message for reconfiguring the RRC. The method described in any one of the appendices 1 through 30. (Note 32) The information indicating whether the aforementioned configuration information is valid is transmitted via a master information block or a system information block. The method described in any one of the appendices 1 through 30. (Note 33) A method implemented by an access network node to communicate with user equipment (UE) via a non-terrestrial network, wherein the method is: Transmitting configuration information that identifies pre-configured uplink resources for use by the UE in the Wireless Resource Control (RRC) idle state, To transmit received information indicating whether the aforementioned configuration information is valid, Includes, The aforementioned information is used by the UE to authenticate whether the configuration information is still valid. method. (Note 34) User equipment (UE) for communication via a non-terrestrial network, wherein the UE is Means for receiving configuration information that identifies pre-configured uplink resources for use by the UE in a wireless resource control (RRC) idle state, Means for authenticating whether the aforementioned configuration information is still valid, A means for determining whether to transmit data using the pre-configured uplink resources in accordance with the authentication, Equipped with, UE. (Note 35) An access network node for communicating with user equipment (UE) via a non-terrestrial network, wherein the access network node is Means for transmitting configuration information that identifies pre-configured uplink resources for use by the UE in a wireless resource control (RRC) idle state, Means for transmitting received information indicating whether the aforementioned configuration information is valid, Equipped with, The aforementioned information is used by the UE to authenticate whether the configuration information is still valid. Access network node.

[0162] This application claims priority based on UK Patent Application No. 2203837.6, filed on 18 March 2022, the disclosure thereof being incorporated herein by reference in its entirety. [Explanation of Symbols]

[0163] 1. Telecommunications Systems 3 Mobile devices 5 NTN nodes 6 base station 7. Data Network 31, 51, 71 Transceiver Circuits 33, 53 Antennas 35 User Interface 36 USIM 37, 57, 77 Control Unit 39, 59, 79 memory 41, 61, 81 Operating Systems 43, 63, 83 Communication control modules 45 Positioning Module 55, 75 Network Interfaces

Claims

1. User equipment (UE) for communication via a non-terrestrial network (NTN), In the first cell, means for receiving configuration information indicating preconfigured uplink resources used by the UE in a Radio Resource Control (RRC) idle state, means for receiving control information for controlling a timer for transmission using the aforementioned pre-configured uplink resources, Means for re-selecting the cell on which the aforementioned UE camps up as a second cell, Means for controlling the effectiveness of the timing advance value corresponding to the timer based on whether it is within the coverage of at least one non-terrestrial cell operated by the non-terrestrial network, In response to the re-selection of the cell, means for authenticating whether the configuration information in the second cell is still valid based on controlling the validity of the timing advance value, A means for determining whether to transmit data using the pre-configured uplink resource in accordance with the authentication, Equipped with, Controlling the effectiveness of the timing advance value includes ignoring the timer when the UE is using a non-terrestrial service or when the UE is camped on to one of the at least one non-terrestrial cell. UE.

2. The control information includes cell information indicating a plurality of cells for which the configuration information is valid, The authentication means is configured to authenticate using the cell information. The UE according to claim 1.

3. The control information includes cell information indicating multiple cells that are identical to or substitutes for the first cell corresponding to the configuration information. The authentication means is configured to authenticate using the cell information when the UE is outside the coverage of the first cell or within the coverage of the second cell among the plurality of cells indicated by the cell information. The UE according to claim 1.

4. The control information includes coverage information relating to coverage provided via at least one non-terrestrial cell operated by the non-terrestrial network, The authentication means is configured to authenticate using the coverage information. The UE according to claim 1.

5. The aforementioned coverage information is, Ephemeris information relating to at least one non-ground cell, Information indicating the coverage start time associated with at least one non-terrestrial cell, Information indicating the coverage end time associated with at least one non-terrestrial cell, or Timing advance parameters associated with the at least one non-ground cell, Including at least one of the following: The UE according to claim 4.

6. Means for applying the configuration information when the UE camps on to a cell belonging to at least one non-ground cell based on the coverage information, Means for maintaining the configuration information when the UE is outside the coverage based on the coverage information, Equipped with, The UE according to claim 4 or 5.

7. The system includes means for receiving information indicating the number of times the UE is permitted to miss the pre-configured uplink resource before releasing the configuration information, The number of opportunities refers to the number of opportunities within at least one predetermined period while the UE is within the coverage of the at least one non-terrestrial cell. The UE according to claim 4 or 5.

8. The control information includes location information to indicate the area where the configuration information is valid. The authentication means is configured to authenticate using the location information. The UE according to claim 1.

9. A method for user equipment (UE) to communicate via a non-terrestrial network (NTN), In the first cell, configuration information indicating preconfigured uplink resources used by the UE in the Radio Resource Control (RRC) idle state is received, Receiving control information for controlling a timer for transmission using the aforementioned pre-configured uplink resources, The aforementioned UE re-selects the cell to which it camps as the second cell, The effectiveness of the timing advance value corresponding to the timer is controlled based on whether it is within the coverage of at least one non-terrestrial cell operated by the non-terrestrial network, In response to the re-selection of the cell, authentication is performed to determine whether the configuration information in the second cell is still valid, based on controlling the validity of the timing advance value. In accordance with the authentication, it is determined whether to transmit data using the pre-configured uplink resource, Includes, Controlling the effectiveness of the timing advance value includes ignoring the timer when the UE is using a non-terrestrial service or when the UE is camped on to one of the at least one non-terrestrial cell. method.

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