Transmission for time synchronization

Abstract

Disclosed is a method including: defining an indexed table defining settings defining durations of segments included in a transmission period for an elevation angle of a terminal device relative to a serving satellite, the segments including at least one transmission segment and at least one segment for at least one timing advance adjustment, the indexed table including a plurality of elevation angle ranges having corresponding settings; obtaining notification regarding an index defining a setting applicable to the elevation angle of the terminal device; scheduling a transmission, the transmission being an uplink transmission; and receiving a transmission from the terminal device in accordance with the setting applied to the elevation angle of the terminal device.

Description

Technical Field

[0001] The following exemplary embodiments relate to wireless communication and timing synchronization for transmission.

Background Art

[0002] Wireless communication networks such as cellular communication networks enable devices to move freely from one area to another. Data transmitted using a wireless communication network can follow a transmission cycle setting. Therefore, it is necessary to synchronize the timing of the transmission cycle between the receiving side and the transmitting side.

Summary of the Invention

[0003] The scope of protection required by various embodiments of the present disclosure is defined by the independent claims. If there are exemplary embodiments and features described herein that do not fall within the scope of the independent claims, they are interpreted as useful examples for understanding the various embodiments of the present disclosure.

[0004] According to a first aspect, there is provided an apparatus comprising at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code cause the at least one processor to obtain, for the estimated elevation angle of a terminal device with respect to a serving satellite, a setting that defines the duration of segments included in a transmission period, the segments including at least one transmission segment and at least one timing advance adjustment segment; transmit an uplink transmission to an access node included in a non-terrestrial network during the period of the at least one transmission segment; and adjust the timing advance of the uplink transmission during the period of the at least one timing advance adjustment segment.

[0005] According to a second embodiment, the device is provided, which includes means for acquiring a setting that defines the duration of segments included in a transmission period with respect to the estimated elevation angle of a terminal device with respect to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; means for transmitting an uplink transmission to an access node included in a non-terrestrial network during the duration of the at least one transmission segment; and means for adjusting the timing advance of the uplink transmission during the duration of the at least one timing advance adjustment segment.

[0006] A third aspect of the invention provides a method for obtaining a setting that defines the duration of a segment included in a transmission period with respect to the estimated elevation angle of a terminal device with respect to a serving satellite, wherein the segment includes at least one transmission segment and at least one segment for at least one timing advance adjustment; transmitting an uplink transmission to an access node included in a non-terrestrial network during the duration of the at least one transmission segment; and adjusting the timing advance of the uplink transmission in the at least one timing advance adjustment segment.

[0007] According to a fourth aspect, a computer program is provided which includes instructions for the device to perform the following actions: obtain a setting that defines the duration of segments included in a transmission period with respect to the estimated elevation angle of the terminal device relative to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; transmit an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment; and adjust the timing advance of the uplink transmission during the at least one timing advance adjustment segment.

[0008] According to a fifth aspect, a computer program product is provided which includes instructions for causing the device to perform the following actions: obtain a setting that defines the duration of segments included in a transmission period for the estimated elevation angle of the terminal device with respect to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; transmit an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment; and adjust the timing advance of the uplink transmission during the duration of the at least one timing advance adjustment segment.

[0009] According to a sixth aspect, a computer program is provided which stores instructions for performing the following: obtaining a setting that defines the duration of segments included in a transmission period for the estimated elevation angle of a terminal device with respect to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; transmitting an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment; and adjusting the timing advance of the uplink transmission during the duration of the at least one timing advance adjustment segment.

[0010] According to a seventh aspect, a non-transient, computer-readable medium is provided which includes program instructions for causing the device to perform the following actions: obtain a setting that defines the duration of segments included in a transmission period for the estimated elevation angle of the terminal device with respect to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; transmit an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment; and adjust the timing advance of the uplink transmission during the duration of the at least one timing advance adjustment segment.

[0011] According to the eighth aspect, a non-transient computer-readable medium is provided which stores program instructions for performing: obtaining a setting that defines the duration of segments included in a transmission period for the estimated elevation angle of a terminal device with respect to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for at least one timing advance adjustment; transmitting an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment; and adjusting the timing advance of the uplink transmission during the duration of the at least one timing advance adjustment segment.

[0012] According to the ninth aspect, a device is provided comprising at least one processor and at least one memory containing computer program code, wherein the at least one memory and computer program code are configured to cause the at least one processor to define an indexed table that defines settings for the elevation angle of a terminal device relative to a serving satellite, defining the duration of segments included in a transmission period, wherein the segments include at least one transmission segment and at least one timing advance adjustment segment, and the indexed table includes a range of elevation angles having corresponding settings; to obtain notification of an index that defines settings applied to the elevation angle of the terminal device; to schedule a transmission, wherein the transmission is an uplink transmission; and to receive a transmission from a terminal device in accordance with settings applied to the elevation angle of the terminal device.

[0013] According to a tenth aspect, a device is provided comprising: means for defining an indexed table that defines settings for the elevation angle of a terminal device with respect to a serving satellite, the settings for which a segment is included in a transmission period, wherein the segment includes at least one transmission segment and at least one timing advance adjustment segment, and the indexed table includes a range of elevation angles having corresponding settings; means for obtaining notification of an index that defines settings applied to the elevation angle of the terminal device; means for scheduling a transmission, wherein the transmission is an uplink transmission; and means for receiving a transmission from a terminal device in accordance with settings applied to the elevation angle of the terminal device.

[0014] According to the eleventh aspect, a method is provided which includes defining an indexed table that defines a setting for the elevation angle of a terminal device relative to a serving satellite, defining a segment that includes at least one transmission segment and at least one segment for timing advance adjustment, wherein the indexed table includes a range of elevation angles having the corresponding setting; obtaining notification of an index that defines a setting applied to the elevation angle of the terminal device; scheduling a transmission, wherein the transmission is an uplink transmission; and receiving a transmission from the terminal device in accordance with the setting applied to the elevation angle of the terminal device.

[0015] According to a twelfth aspect, a computer program is provided which includes instructions to cause a device to perform at least the following actions: define an indexed table that defines a setting that defines the duration of a segment included in a transmission period for the elevation angle of a terminal device relative to a serving satellite, wherein the segment includes at least one transmission segment and at least one timing advance adjustment segment, and the indexed table includes a range of elevation angles having the corresponding setting; obtain notification of an index that defines a setting applicable to the elevation angle of a terminal device; schedule a transmission, wherein the transmission is an uplink transmission; and receive a transmission from a terminal device according to a setting applicable to the elevation angle of the terminal device.

[0016] According to the 13th aspect, a computer program product is provided which includes instructions to cause a device to perform the following actions: define an indexed table that defines a setting that defines the duration of a segment included in a transmission period for the elevation angle of a terminal device relative to a serving satellite, wherein the segment includes at least one transmission segment and at least one timing advance adjustment segment, and the indexed table includes a range of elevation angles having the corresponding setting; obtain notification of an index that defines a setting that applies to the elevation angle of the terminal device; schedule a transmission, wherein the transmission is an uplink transmission; schedule a transmission, and receive a transmission from the terminal device according to the setting that applies to the elevation angle of the terminal device.

[0017] According to the 14th aspect, a computer program is provided which stores instructions for performing at least defining an indexed table that defines a setting that defines the duration of segments included in a transmission period for an elevation angle of a terminal device relative to a serving satellite, wherein the segments include at least one transmission segment and at least one segment for timing advance adjustment, and the indexed table includes a range of elevation angles having the corresponding setting; obtaining notification of an index that defines a setting that applies to the elevation angle of the terminal device; scheduling a transmission, wherein the transmission is an uplink transmission; and receiving a transmission from the terminal device according to the setting that applies to the elevation angle of the terminal device.

[0018] According to the 15th aspect, a non-transient computer-readable medium is provided which includes program instructions for causing the device to perform at least the following: define an indexed table that defines a setting that defines the duration of a segment included in a transmission period for the elevation angle of the terminal device relative to a serving satellite, wherein the segment includes at least one transmission segment and at least one timing advance adjustment segment, and the indexed table includes a range of elevation angles having the corresponding setting; obtain notification of an index that defines a setting that applies to the elevation angle of the terminal device; schedule a transmission, wherein the transmission is an uplink transmission; and receive a transmission from the terminal device according to a setting that applies to the elevation angle of the terminal device.

[0019] According to the 16th aspect, a non-transient computer-readable medium is provided which stores program instructions for performing: defining an indexed table that defines settings for the elevation angle of a terminal device relative to a serving satellite, the segments comprising at least one transmission segment and at least one segment for timing advance adjustment, wherein the indexed table comprises a range of elevation angles having corresponding settings; obtaining notification of an index that defines settings applied to the elevation angle of a terminal device; scheduling a transmission, the transmission being an uplink transmission; and receiving a transmission from a terminal device according to settings applied to the elevation angle of the terminal device. [Brief explanation of the drawing]

[0020] The present disclosure will be described in more detail below with reference to embodiments and accompanying drawings. [Figure 1] Figure 1 shows an exemplary embodiment of a wireless access network. [Figure 2]FIG. 2 is a diagram showing an exemplary embodiment of a transmission period and a synchronization period. [Figure 3A] FIG. 3A shows a diagram according to an exemplary embodiment regarding the change of a timing advance value. [Figure 3B] FIG. 3B shows a graph according to an exemplary embodiment of a Doppler shift during a transmission period. [Figure 4] FIG. 4 is a diagram showing a flowchart according to an exemplary embodiment. [Figure 5] FIG. 5 is a diagram showing an exemplary embodiment of a transmission period. [Figure 6A] FIG. 6A is a diagram showing the change of a timing advance for different transmission periods at different elevation angles. [Figure 6B] FIG. 6B is a diagram showing the change of a timing advance for different transmission periods at different elevation angles. [Figure 6C] FIG. 6C is a diagram showing the change of a timing advance for different transmission periods at different elevation angles. [Figure 6D] FIG. 6D is a diagram showing the change of a timing advance for different transmission periods at different elevation angles. [Figure 6E] FIG. 6E is a diagram showing the change of a timing advance for different transmission periods at different elevation angles. [Figure 6F] FIG. 6F is a diagram showing an exemplary embodiment of the movement of a satellite and possible positions of a terminal device. [Figure 6G] FIG. 6G shows an exemplary graph for evaluating the influence of the use of an azimuth angle. [Figure 7A] FIG. 7A shows an exemplary embodiment in which a terminal device performs a timing advance adjustment. [Figure 7B] FIG. 7B shows an exemplary embodiment in which a terminal device performs a timing advance adjustment. [Figure 8] FIG. 8 is a diagram showing a signaling flowchart. [Figure 9] FIG. 9 is a diagram showing a signaling flowchart. [Figure 10]Figure 10 shows an exemplary embodiment of the apparatus. [Figure 11] Figure 11 shows an exemplary embodiment of the apparatus. [Modes for carrying out the invention]

[0021] The following embodiments are illustrative. While this specification may refer to “a certain,” “one,” or “several” embodiments in some places, this does not necessarily mean that each reference is made to the same embodiment, or that certain features apply to only one embodiment. Other embodiments may also be provided by combining single features from different embodiments.

[0022] As used in this application, the term “circuit” means (a) hardware-only circuit implementations, such as implementations in analog and / or digital circuits only; (b) combinations of circuitry and software (and / or firmware), for example (where applicable): (i) a combination of processors, or (ii) a part of processor(s) / software, including digital signal processors, software, and memory(s), that work together to enable a device to perform various functions; and (c) all circuits that require software or firmware for operation, including cases where the software or firmware is not physically present, such as a microprocessor(s) or a part of a microprocessor(s). This definition of “circuit” applies to all uses of the term in this application. As a further example, as used in this application, the term “circuit” also covers a processor(s) or a part of a processor and the software and / or firmware implementation associated with it(s). Furthermore, the term “circuit” also covers, for example, a baseband integrated circuit or application processor integrated circuit for a mobile phone, or a similar integrated circuit in a server, cellular network equipment, or other network equipment, if applicable to a specific element. The embodiments of the circuit described above can also be considered embodiments that provide means for carrying out embodiments of the methods or processes described herein.

[0023] The techniques and methods described herein can be implemented by various means. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In the case of hardware implementation, the device(s) of the embodiment may be implemented inside one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In the case of firmware or software, implementation can be done through at least one chipset module (e.g., procedure, function, etc.) that performs the functions described herein. Software code may be stored in a memory unit and executed by a processor. The memory unit may be implemented within the processor or outside the processor. In the latter case, it may be coupled to the processor in a communicative manner via any suitable means. Furthermore, the components of the system described herein may be rearranged and / or complemented by additional components to facilitate the achievement of various embodiments, etc., described herein, and these are not limited to the exact configuration shown in the given figures, as will be understood by those skilled in the art.

[0024] The embodiments described herein can be implemented in communication systems such as Global Mobile Communication Systems (GSM) or other second-generation cellular communication systems, Universal Mobile Communication Systems (UMTS, 3G) based on basic broadband code division multiplexing access (W-CDMA), High-Speed ​​Packet Access (HSPA), Long-Term Evolution (LTE), LTE-Advanced, systems based on the IEEE 802.11 specification, systems based on the IEEE 802.15 specification, Narrowband Internet of Things (NB-IoT), LTE-M including enhanced machine-type communications (eMTC), and / or fifth-generation (5G) mobile communication systems or cellular communication systems. However, the embodiments are not limited to the systems given as examples, and those skilled in the art can apply the solutions to other communication systems with the necessary characteristics.

[0025] Figure 1 shows a simplified example of a system architecture, illustrating several elements and functional entities, all of which are logical units, and their implementation may differ from that shown. The connections shown in Figure 1 are logical connections, and actual physical connections may differ. It will be obvious to those skilled in the art that the system may also consist of functions and structures other than those shown in Figure 1. The example in Figure 1 illustrates a portion of an exemplary wireless access network.

[0026] Figure 1 shows an access node (e.g., node B) 104 providing a cell and terminal devices 100 and 102 configured to wirelessly connect to it via one or more communication channels within the cell. The access node 104 may also be called a wireless access node or node. The physical link from the terminal devices to node B, for example, is called an uplink or reverse link, and the physical link from node B to the terminal devices, for example, is called a downlink or forward link. It should be understood that node B or its functions can be implemented using any entity such as a node, host, server, or access point suitable for such an application. While this exemplary embodiment describes one cell, it should be noted that for simplicity of explanation, in some exemplary embodiments, a single access node may provide multiple cells.

[0027] A communication system may include multiple nodes, for example, Node B, in which case Node B may be configured to communicate with each other via wired or wireless links designed for that purpose. These links can be used for signaling purposes. For example, Node B is a computing device configured to control the wireless resources of the communication system to which it is coupled. For example, Node B may also be called other types of interface devices, including base stations, access points, or relay stations capable of operating in a wireless environment. For example, Node B includes or is coupled to a transceiver. For example, a connection is provided from the transceiver of Node B to an antenna unit that establishes a bidirectional wireless link to user equipment. The antenna unit may include multiple antennas or antenna elements. For example, Node B is further connected to a core network 110 (CN or next-generation core NGC). Depending on the system, the peer device on the CN side may be a serving gateway (S-GW, for routing and forwarding user data packets), a packet data network gateway (P-GW) for providing connectivity of terminal equipment (UE) to an external packet data network, or a mobile management entity (MME).

[0028] A terminal device (also called a UE, user device, user terminal, or user equipment) represents one type of device to which resources on an air interface are allocated and assigned. Therefore, any functions described herein in conjunction with a terminal device may be implemented in conjunction with corresponding devices such as relay nodes. An example of such a relay node is a Layer 3 relay (self-backhauling relay) directed to a base station. Another example of such a relay node is a Layer 2 relay. Such a relay node may include a terminal device section and a distributed unit (DU) section. A CU (centralized unit) can coordinate the operation of the DU, for example, via an F1AP interface.

[0029] Terminal devices may refer to portable computing devices, including wireless mobile communication devices that operate with or without a subscriber identification module (SIM), or embedded SIM, or eSIM, and include, but are not limited to, mobile stations (cell phones), smartphones, personal digital assistants (PDAs), handsets, devices using wireless modems (such as alarm or measuring devices), laptops and / or touchscreen computers, tablets, game consoles, notebooks, and multimedia devices. User devices may also be exclusive or near-exclusive uplink-only devices, such as cameras or camcorders that load images or video clips onto the network. Terminal devices may also be devices capable of operating in an Internet of Things (IoT) network. An IoT network is a scenario in which things are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. Terminal devices can also utilize the cloud. In some applications, terminal devices include small portable devices with wireless components (such as watches, earphones, or glasses), with computing performed in the cloud. A terminal device (or, in some embodiments, a Layer 3 relay node) is configured to perform one or more user device functions.

[0030] The various technologies described herein can also be applied to cyber-physical systems (CPS) (systems of collaborative computing elements that control physical entities). CPS can enable the implementation and use of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects located in different places. Mobile cyber-physical systems are a subcategory of cyber-physical systems in which the physical system has its own mobility. Examples of mobile physical systems include mobile robots and electronic devices that are moved by humans or animals.

[0031] Furthermore, although the device is shown as a single entity, it can also implement different units, processors, and / or memory units (not all of which are shown in Figure 1).

[0032] 5G utilizes multiple-input, multiple-output (MIMO) antennas, enabling more base stations and nodes than LTE (the so-called small cell concept), including macrosites that work in conjunction with smaller base stations, and employs various radio technologies depending on service needs, use cases, and available frequencies. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, various data sharing methods, traffic safety, various sensors, and various forms of mechanical applications such as (large-scale) mechanical communications (mMTC) including real-time control. 5G has multiple radio interfaces, including sub-6GHz, centimeter wave (cmWave), and millimeter wave (mmWave), and is expected to be able to integrate with existing legacy radio access technologies such as LTE. Integration with LTE may be implemented, at least in the initial stages, as a system where macro coverage is provided by LTE, and 5G radio interface access is provided from small cells through aggregation into LTE. In other words, 5G is planned to support both RAT-to-RAT operations (such as LTE-5G) and RI-to-RI operations (such as sub-6GHz-centimeter wave and sub-6GHz-centimeter wave-millimeter wave). One concept that is expected to be used in 5G networks is network slicing. This slicing allows for the creation of multiple independent, dedicated virtual subnets (network instances) within the same infrastructure to run services with different latency, reliability, throughput, and mobility requirements.

[0033] The current architecture of LTE networks is fully distributed wirelessly and fully centralized in the core network. Low-latency applications and services in 5G will require bringing content closer to the wireless, potentially leading to local breakout and multi-access edge computing (MEC). 5G will enable analysis and knowledge generation at the data source. This approach requires leveraging resources that are not constantly connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for hosting applications and services. It also has the ability to store and process content near cellular subscribers, reducing response times. Edge computing covers a wide range of technologies, including wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer ad-hoc networking, local cloud / fog computing, grid / mesh computing, dew computing, mobile edge computing, cloudlet distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (where large-scale connectivity and / or latency are critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, and healthcare applications).

[0034] The communication system can also communicate with and / or utilize services provided by other networks, such as the public switched telephone network and the Internet. The communication network can also support the use of cloud services, for example, by implementing at least a portion of its core network operations as a cloud service (indicated by "cloud" in Figure 1). Furthermore, the communication system may include a central control entity and provide facilities for different operators' networks to cooperate, for example, in spectrum sharing.

[0035] Edge cloud can be brought into a radio access network (RAN) by leveraging network function virtualization (NFV) and software-defined networking (SDN). Using edge cloud may mean that access node operations are performed on servers, hosts, or nodes that are operablely coupled to remote radio heads or base stations, including the radio portion, at least partially. Node operations may also be distributed across multiple servers, nodes, or hosts. The application of a cloudRAN architecture allows real-time functions of the RAN to be performed on the RAN side (in the distributed unit DU104), while non-real-time functions are performed centrally (in the centralized unit CU108).

[0036] Furthermore, it should be understood that the labor distribution between core network operations and base station operations may differ from, or even be nonexistent in, LTE. Other technologies that may change how networks are built and managed, such as big data and all-IP, may also be used. 5G (or New Radio, NR) networks are designed to support multiple layers, and MEC servers can be placed between the core and base stations or node B (gNB). It should also be understood that MEC can be applied to 4G networks.

[0037] 5G can also utilize satellite communications to enhance or complement the coverage of 5G services. For example, it can provide backhaul and service availability in areas without terrestrial coverage. Anticipated use cases include providing service continuity for M2M (Machine-to-Machine) and IoT (Internet of Things) devices, or for passengers in vehicles, and / or ensuring the service availability of critical communications, and / or future rail / maritime / air communications. Satellite communications can utilize geostationary (GEO) satellite systems, but can also utilize low Earth orbit (LEO) satellite systems, such as megaconstellations (systems with hundreds of (nano) satellites). Satellite 106, including a constellation, may carry a gNB that creates ground cells, or at least a portion of a gNB. Alternatively, satellite 106 may be used to relay signals from one or more cells to Earth. Ground cells can be accessed via ground relay nodes 104, or by gNBs located on the ground or satellite, or by gNBs where part is on a satellite (e.g., DU) and part is on the ground (e.g., CU). Alternatively, a High Altitude Platform Station (HAPS) system can also be used. A HAPS can be understood as a radio station stationed at a fixed point relative to the Earth, installed on an object at an altitude of 20-50 km. Alternatively, a HAPS may move relative to the Earth. For example, a lightweight, solar-powered aircraft or airship at an altitude of 20-25 kilometers can be used to provide broadband access via a HAPS by operating it continuously for several months.

[0038] It should be noted that the system shown is an example of a wireless access system, and the system may include multiple, for example, Node B, terminal devices may have access to multiple wireless cells, and the system may include other devices such as physical layer relay nodes or other network elements. For example, at least one of Node B may be, for example, Home Node B. Furthermore, multiple different types of wireless cells may be provided in the geographical area of ​​the wireless communication system, as well as multiple wireless cells. Wireless cells may be macrocells (or umbrella cells), which are large cells typically with a diameter of up to tens of kilometers, or they may be small cells such as microcells, femtocells, picocells, etc. Node B in Figure 1, for example, can provide these cells. A cellular wireless system can be implemented as a multi-layer network including multiple types of cells. In some exemplary embodiments, in a multi-layer network, one access node provides one or more cells, and therefore multiple, for example, Node B are required to provide such a network structure.

[0039] To meet the need to improve the deployment and performance of communication systems, the concept of a "plug-and-play" node B has been introduced, for example. For example, a network that can use a "plug-and-play" node B may include a home node B (e.g., H node B) in addition to a home node B gateway (HNB-GW) (not shown in Figure 1). The HNB gateway (HNB-GW) can be installed within the operator's network and can aggregate traffic from multiple HNBs and return it to the core network.

[0040] A non-terrestrial network (NTN) may refer to a network or segment of a network that uses radio frequency (RF) resources of a satellite or unmanned aerial system (UAS). A satellite or UAS can provide services on Earth (e.g., NR services) via one or more satellite beams and one or more cells (e.g., NR cells) spanning a given service area surrounded by the satellite's field of view. A service link, i.e., a radio link, may exist between the satellite and one or more terminal devices within the target service area. Furthermore, a feeder link, i.e., a radio link, may exist between the satellite and one or more satellite gateways. A satellite gateway can, for example, connect the satellite to a public data network. gNB functionality may be provided, for example, in the satellite, gateway, and / or data network, and may have access node functionality, e.g., gNB functionality. A non-terrestrial network (NTN) can be supported by the 5G standard. For example, a gNB, which is a 5G access node, can be deployed on a satellite to enable coverage to areas that may otherwise not be covered by cellular communication networks. This allows 5G signals to be beamed down from space, enhancing the ground infrastructure of wireless communication networks. It can also help improve the reliability of wireless communications during disasters such as earthquakes, where ground access nodes may be damaged. Note that in some alternative embodiments, the gNB may be located on the ground and have backhaul connectivity via satellite.

[0041] There are various types of artificial satellites. For example, some satellites have been orbiting the Earth for decades, operating at an altitude of 36,000 km. There are also satellites called low Earth orbit (LEO) satellites. These satellites operate between 500 and 2000 kilometers above the Earth. Some LEO satellites operate at an altitude of approximately 600 kilometers above the Earth. Lower orbits allow satellites to receive and transmit data quickly, thus reducing latency.

[0042] The Internet of Things (IoT) can be understood as a network of physical objects connected to each other and / or to the Internet. These physical objects are devices, also called IoT devices, that connect to each other, for example, using cellular communication networks. Such devices can be embedded in mobile devices, industrial equipment, environmental sensors, medical devices, and so on. Furthermore, such devices may include various sensors that generate data related to each device and provide it to other devices; therefore, devices can be understood as the "things" of the IoT. Devices included in the IoT are used to provide an interface between the surrounding physical environment and the digital environment. These devices can have a variety of technical capabilities, and some of the devices used in the IoT are, for example, low-cost devices with limited hardware resources.

[0043] Cellular communication networks can be used to connect devices used in IoT environments. For example, Narrowband IoT (NB-IoT) is a cellular standard for low-power, wide-area, LPWA, and machine-to-machine networks. NB-IoT is used for low-throughput, latency-tolerant applications such as meters and sensors. NB-IoT can be deployed, for example, within existing LTE bands, as guard bands between two regular LTE carriers, or in standalone mode. Enhanced Machine-Type Communications (eMTC) can also be used for IoT, optimized for lower complexity, lower power consumption, wider coverage, and higher device density. eMTC can coexist seamlessly with other cellular network services such as regular mobile broadband. NTN also anticipates the use of both NB-IoT and eMTC.

[0044] In a narrowband physical uplink shared channel (NPUSCH) configuration, repetitions may be used to improve coverage. Multiple repetitions may include a transmit period followed by a synchronization period. Figure 2 shows exemplary embodiments of transmit and synchronization periods, which can be understood as periods having predetermined lengths. When a terminal device transmits on the uplink (UL), a transmit period 210 is followed by a synchronization period 220, followed by another transmit period 210, followed by another synchronization period 220. In this exemplary embodiment, the transmit period 210 has a predetermined duration X as 256 ms, and the synchronization period 220 has a predetermined duration Y as 40 ms. Note that in several other exemplary embodiments, the periods may similarly have other durations. Thus, in this exemplary embodiment, the NPUSCH is configured to have a total length of NPUSCH transmit of 256 ms or less before a 40 ms gap in which the terminal device performs synchronization by adjusting the timing advance (TA) and / or Doppler shift compensation. In this exemplary embodiment, once the TA is determined during the synchronization period 220, the terminal device does not adjust the TA during the transmission period 210. Furthermore, the terminal device does not adjust the TA during a gap if the transmissions before and after the gap are part of the same set of repetitions.

[0045] In some exemplary embodiments, NB-IoT / eMTC technology can be deployed in NTN scenarios such as scenarios in which different types of satellites are used in transparent mode and / or regenerative mode. Transparent mode can be understood as a mode in which access nodes such as gNBs remain on Earth and satellites relay signals. Regenerative mode can be understood as a mode in which access nodes such as gNBs become payloads on satellites. Thus, IoT NTN can be understood as a deployment in an NTN where LEO or GEO satellites provide service coverage to ground-based terminal devices.

[0046] In IoT NTN, the orbital velocity of the LEO satellite is, for example, approximately 7,800 m / s. Due to the high speed of the satellite's movement, the Doppler shift and timing advance (TA) values ​​change significantly. The TA value may also be a time value such as microseconds. Figure 3A shows a diagram of an exemplary embodiment illustrating how the amount of TA value may change during a transmission period of X = 256 ms at different elevation angles from 10 to 90 degrees. In this exemplary embodiment, the altitude of the LEO satellite is 600 km, the beam radius is 100 km, and the carrier frequency is 2 GHz. In Figure 3A, the change in TA value ΔTA is defined as the difference between the initial TA value at a given elevation angle and the new TA value after the transmission period. For example, as can be seen from Figure 3A, the amount of change in TA value exceeds the maximum allowable range, i.e., half of the cyclic prefix (CP) length. Half of the CP length in this exemplary embodiment is 2.35 μs. In this exemplary embodiment, if the NPUSCH configuration uses the initial TA over the transmission period X, the change in TA value during the transmission period results in a large TA error. Therefore, the terminal equipment may experience uplink desynchronization, potentially causing significant interference on the receiving end of the transmission. Figure 3B shows a graph of an exemplary embodiment of Doppler shift change during a 256 ms transmission period. Figure 3B shows that the effect of satellite speed on Doppler shift is relatively small, as the Doppler shift error is smaller than the subcarrier spacing (SCS) of 15 kHz. Therefore, mitigating the effects of large TA changes during long transmission periods is beneficial for enhancing the temporal synchronization of IoT at NTN.

[0047] To mitigate the effects of large TA changes during long transmission periods, the transmission period can be divided. The division can be such that timing drift within a segment does not violate timing requirements, and therefore can be based on, for example, a cyclic prefix (CP). Figure 4 shows a flowchart of an exemplary embodiment of such a transmission period division. First, in S1, the network determines the timing drift as a function of elevation and satellite altitude. The network may be, for example, access nodes included in the network, other components included in the network such as a 5G network, or a combination of network components as described in the exemplary embodiment of Figure 1. Next, in S2, the network defines the lengths of the transmission segments included in the transmission period to be divided into segments. These lengths are defined as a function of elevation. For example, a first period P1 may be defined with respect to a first elevation, and a second period P2 may be defined with respect to a second elevation. Optionally, the network may provide terminal devices with an indexed table having the lengths of the segments included in the transmission period and elevation. This provision is performed, for example, by broadcasting the indexed table or by using signaling specific to the terminal devices.

[0048] Next, in S3, the elevation angle of the terminal device is determined. The elevation angle may be determined before scheduling the uplink transmission. The uplink transmission may contain data or information. Optionally, the terminal device may transmit its position and / or elevation angle to the network. Alternatively, the network may obtain the terminal device's position and / or elevation angle by other appropriate means. After determining the elevation angle at the start of the next transmission, the network may inform the terminal device which index of the indexed table to use when the indexed table is transmitted to the terminal device. Alternatively, the network may provide the terminal device with information about the index, such as the segment length. Also, optionally, the terminal device may determine its elevation angle based on Global Navigation Satellite System (GNSS) information and satellite ephemeris data, and select the corresponding index of the indexed table when the indexed table is transmitted to the terminal device by the network, such as an access node. The terminal device can then transmit information about the elevation angle and / or the selected index to the network. This information may be transmitted prior to the uplink transmission performed by the terminal device to the network, such as an access node like a gNB. Furthermore, as an option, terminal devices and / or networks may select or define multiple indexes in an indexed table for subsequent transmissions performed by the terminal devices to the network. Note that the selection of segment length may affect the number of repetitions accommodated within the transmission period, and therefore, if terminal devices autonomously select indexes, the network may need to adjust its scheduling.

[0049] In S4, the terminal device initiates uplink transmission and applies the transmission segment. Optionally, in S5, the terminal device may also perform any necessary TA adjustments after the transmission segment. TA adjustments can also be performed after each transmission segment. Because the network is aware of the applied transmission segment length, it can determine when transmission ends and wait for the reception of the next timing advance adjustment transmission.

[0050] As mentioned above, because satellites move at high speeds, the time axis (TA) can change significantly during uplink transmission of packets that may be data packets. Therefore, this TA change must be adjusted to keep the uplink timing error within a predetermined tolerance of less than half the cyclic prefix length. For example, if the repeatable transmission period is 256 ms, the terminal equipment performing the uplink transmission of packets may require multiple TA adjustments due to the small elevation angle relative to the satellite. This adjustment can be performed, for example, by dividing the transmission period into multiple segments, allowing the terminal equipment to perform TA adjustments for TA drift caused by satellite movement.

[0051] It should be noted that the transmission period may include one or more transmission segments and one or more TA adjustment periods. A TA adjustment period may also be understood as a TA adjustment gap or a segment for timing advance adjustment. A TA adjustment period may occur, for example, between two transmission segments, after a transmission segment, and / or before a transmission segment. Also, it should be noted that the elevation angle of the terminal equipment may be the elevation angle relative to the serving satellite if the terminal equipment is served by an access node included in NTN.

[0052] Figure 5 shows an exemplary embodiment of dividing the transmission period. In this exemplary embodiment, the transmission period is denoted as X, and the synchronization period following the transmission period X is denoted as Y. In this exemplary embodiment, the entire duration of the transmission period X, which may be, for example, 256 ms, is divided into multiple segments 532 of the transmission period. The segments of the transmission period are P i This can be expressed as follows, where i indicates the i-th segment. Between the two segments 532, there is a TA adjustment period 534. The TA adjustment period is sometimes denoted as W. Figure 5 shows a timeline. Along the timeline, the timing of the segments included in the transmission period as seen from the terminal device 520 and the timing of the segments included in the transmission period as seen from the access node 510, which is a gNB in ​​this exemplary embodiment, are illustrated. The access node is included in the network.

[0053] The length of the adjustment period 534 may depend on the length of the transmission period, satellite altitude, and / or elevation angle. Furthermore, if there are many segments 532 with shorter transmission periods, the adjustment period 534 may be correspondingly shorter compared to when the segments 532 of the transmission period are longer and the adjustment period 534 is also longer. This is applicable when TA drift is maintained in a similar manner for both short and long durations of the transmission period. The duration of the adjustment period 534 is further determined to be sufficient to accommodate the changes in TA during the transmission period segments 532.

[0054] In this exemplary embodiment, in UL transmission, timing deviations within the CP length of orthogonal frequency division multiplexing (OFDM) symbols are permissible. Therefore, the timing lead error of the terminal device is within the range of [-1 / 2, 1 / 2] CP length. For time-synchronized links, the TA is adjusted before drifting by half the CP length. For example, if the CP length is 4.7 μs, as in NB-IoT, a TA error of less than 2.35 μs does not affect uplink data reception. Therefore, in NB-IoT systems, the TA change during a continuous UL transmission period must be kept below the permissible error of 2.35 μs. As mentioned above, the TA change depends on the elevation angle. For example, the magnitude of ΔTA increases as the elevation angle decreases, as a lower elevation angle results in a higher TA drift rate. Therefore, the appropriate length of the transmission segment period can be determined based on the elevation angle so that ΔTA remains within the permissible range.

[0055] Figure 5 illustrates time point 502, when the first transmission segment 532 of the transmission period is in progress at the terminal device, but the first segment 532 has not yet started at the access node. At time point 504, the time adjustment period 534 at the terminal device has ended, but segment 532 is still in progress at the access node. Next, at time point 506, while the second segment 532 is in progress at the terminal device, the first adjustment period 534 at the access node has ended. In this exemplary embodiment, the period between time points 504 and 506 can be understood as a time adjustment (TA).

[0056] Figures 6A–6E show the change in TA over different transmission periods at different elevation angles. In these figures, the elevation angles vary from 10 to 90 degrees, and the terminal equipment is connected to a LEO satellite at an altitude of 600 km. The elevation angle of the terminal equipment can be used to determine the setting of the period applied to the segment of the transmission period. First, Figure 6A shows a graph with an initial elevation angle of 10 degrees. Figure 6B shows a graph with an initial elevation angle of 30 degrees. Figure 6C shows a graph with an initial elevation angle of 50 degrees. Figure 6D shows a graph with an initial elevation angle of 70 degrees, and Figure 6E shows a graph with an initial elevation angle of 90 degrees. As shown in Figures 6A–6E, the maximum transmission period that satisfies the condition can be formulated as |ΔTA| ≤ 2.35 μs. Maximum transmission periods at different initial elevation angles according to exemplary embodiments are also illustrated in Table 1 below.

[0057] [Table 1]

[0058] In Table 1, each row includes an index, elevation angle (or range of elevation angle), segment length, number of segments, and adjustment gap W. In this exemplary embodiment, the segment length, number of segments, and adjustment gap can be adjusted if the condition W > |ΔTA| is satisfied. Therefore, there are multiple examples that satisfy the given conditions. Table 1 may be defined by the network, for example by gNB, or by any other suitable component of the network, to define a pattern of transmission duration. The pattern may be understood as the length of the transmission segment, TA adjustment period, and synchronization period. In this exemplary embodiment, the maximum length of each transmission segment duration can be determined. For example, the second column of Table 1 defines the initial elevation angle, and the third column of Table 1 defines the maximum transmission segment duration length with respect to the initial elevation angle, based on compliance with the half-cyclic prefix limit. The maximum transmission duration is, for example, P iThis can be the duration of the transmission. In this exemplary embodiment, the lowest elevation angle may be used to determine the segment length in each transmission segment, because a lower elevation angle results in a shorter segment. The fourth column of Table 1 defines the required number of TA adjustments between segments over the entire transmission period X. Furthermore, in this exemplary embodiment, the first column of Table 1 defines an index for each predetermined mode indicating the segment length and the number of TA adjustments. Thus, Table 1 can be used by terminal devices to adjust the TA using the index without receiving a TA command TAC from the network, for example, from an access node. Also, when using Table 1, different segment settings can be used during the same transmission period X.

[0059] [Table 2]

[0060] Table 2 is another example of an indexed table and can be considered another version of Table 1. In Table 2, segment lengths and gaps are represented as integers, and segment lengths can be based on the length of radio units (RUs), as shown in Table 2. In Table 2, it is assumed that when the SCS is 15 kHz, the time unit of RU (7 symbols) is one slot with a duration of 0.5 ms. Using this unit time, the segment lengths are shown as integer values ​​in the third column of the table.

[0061] If the sum of all segment periods and adjustment gaps equals the transmission period X, the values ​​in Table 1 or Table 2 can be easily adjusted. For example, this condition is shown as follows:

number

number

[0062] In Figure 6F, in this exemplary embodiment, the movement of the serving satellite is indicated by arrow 610. Circle 620 indicates the installation location of the serving satellite. In the exemplary embodiment described above, the terminal device is located directly below the orbit of the serving satellite. This location is indicated by Y in Figure 6F. This can lead to a worst-case scenario because the TA can change most rapidly at this location. However, if the terminal device is located on one side of the orbit, such as at the location indicated by X, the terminal device will experience slower changes in TA and may not be able to confirm that the satellite has reached an elevation of 90 degrees. In such a case, the position x relative to the satellite orbit can be described using the azimuth angle φ in addition to the elevation angle, as shown in Figure 6F. Since the maximum elevation angle of the terminal device in such exemplary embodiments is less than 90 degrees, for a given azimuth angle, multiple versions of an indexed table, such as Table 1, can be calculated by the network. Thus, by using reports of elevation angle and / or position and / or azimuth angle from the terminal device, the network can know or estimate the azimuth angle of the terminal device and, based on the azimuth angle, determine the best table from among the multiple versions of the table.

[0063] Figure 6G shows an example graph illustrating the evaluation of the effects of using azimuth angles as described above. In the graph, d xThis represents the distance from the terminal device to the satellite's trajectory on the ground. As shown in the diagram, when the distance is 0, for example, as in position Y shown in Figure 6G, the terminal device observes the maximum drift rate. The advantage of using the azimuth angle is that the segment length can be adjusted to match a specific TA change, and therefore, in the worst-case scenario d x Instead of optimizing for =0 (or azimuth angle = 0), we can apply appropriate knowledge to the precise TA drift rate, improving the system's spectral efficiency.

[0064] Figures 7A and 7B illustrate exemplary embodiments in which a terminal device performs TA adjustment during a TA adjustment period 734 that occurs after segment 732 of transmission period X. The adjustment may be performed based on, for example, Table 1. Transmission pattern 710 shows the segments that make up the transmission period with respect to the access node, and transmission pattern 720 shows the segments that are included in the transmission period with respect to the terminal device. In the exemplary embodiment of Figure 7A, the terminal device adjusts so that the TA is shorter. The first TA occurs between time points 742 and 743. After the second segment 732, TA adjustment is performed during the TA adjustment period 734 so that the second TA period begins after the duration of the adjusted segment 738 and ends at time point 746. In comparison, the first TA occurs between time points 744 and 746. Thus, the second TA is shorter than the first TA.

[0065] In the exemplary embodiment shown in Figure 7B, the terminal device is adjusted to lengthen the time adjustment (TA). The first TA occurs between time points 752 and 753. After the second segment 732, the TA adjustment is performed during the TA adjustment period 734 so that the second TA period begins before the end of the duration of the second TA adjustment period 734, i.e., before time point 754. The duration between the end of the second TA adjustment period and time point 754 is illustrated as 736. In comparison, the first TA occurs between time points 754 and 756. Therefore, the second TA is longer than the first TA.

[0066] An indexed table like the one in Table 1 may be determined by the network, for example by an access node; therefore, the table, or the information contained in the table, may be shared by the access node with terminal devices. Based on the indexed table, the length of the segments included in the transmission period is determined, and terminal devices and the network can share signaling regarding the determination of the segment length in the transmission period. Figures 8 and 9 show flowcharts of such signaling in two different exemplary embodiments.

[0067] In the exemplary embodiment shown in Figure 8, there is signaling between the terminal device 810 and the network 820. In this exemplary embodiment, access nodes included in the network 820 send and receive signaling. First, the network defines an indexed table, as shown in 832, such as Table 1. The indexed table may be defined by one or more components of the network, such as access nodes. The indexed table is for adjusting the TA by defining the duration of segments included within the transmission period, and defining the indexed table includes configuring and storing the indexed table. Meanwhile, the terminal device estimates its elevation angle, as shown in 834. The terminal device 810 may estimate its elevation angle to the satellite based on its position, for example, based on GNSS and satellite ephemeris.

[0068] Network 820 sends an indexed table 842 that it defines to terminal device 810, and as a result, terminal device 810 obtains an indexed table that is used to adjust the TA to define the duration of segments included in the transmission period at various elevation angles. In this exemplary embodiment, terminal device 810 obtains the table from an access node such as a gNB. The terminal device can then select a setting from the obtained indexed table to perform the segment duration adjustment to adjust the TA. This setting is selected based on the estimated elevation angle, or based on the estimated elevation angle and the azimuth angle of the terminal device, as shown in 836. Thus, the setting is applied to the estimated elevation angle of the terminal device. Next, terminal device 810 sends a notification 844 of the index of the selected setting to network 820, i.e., in this exemplary embodiment, the notification is sent to the access node. Network 820 then sets the setting based on the indexed table according to the received notification in order to receive the uplink packets transmitted by terminal device 810, as illustrated in 838. This signaling between the terminal device 810 and the network 820 allows the network to know when a segment of the transmission period ends and to determine how many repetitions it can schedule within the transmission period.

[0069] Figure 9 shows another signaling flowchart. This flowchart is according to an exemplary embodiment, in which network 920 determines the settings for segments included within a transmission period to adjust the TA by defining the duration of segments included within the transmission period based on the location of the terminal device 910 or the elevation angle of the terminal device 910. In this exemplary embodiment, access nodes included in network 920 send and receive signaling. First, network 920 defines an indexed table, such as Table 1, as shown in 932. The indexed table may be defined by one or more components of network 920, for example, access nodes. The indexed table is for adjusting the TA by adjusting the duration of segments included within a transmission period, and defining the indexed table includes configuring and storing the indexed table. Network 920 can then use either the location of the terminal device 910, as exemplified in 901, or the elevation angle of the terminal device 910, as exemplified in 904, to select a setting from the indexed table for adjusting the TA by adjusting the duration of segments. If location is used, the terminal device 910 sends a first notification to the access node indicating its location (942). Thus, the access node obtains the location of the terminal device 910 by receiving the first notification. If the elevation angle of the terminal device 910 is used, the terminal device 910 estimates its elevation angle as shown in 934. The terminal device 910 can estimate its elevation angle with respect to a satellite based on its location, for example, based on GNSS and satellite ephemeris. Next, the terminal device 910 may send a second notification to the access node indicating its elevation angle (944). In this way, the access node obtains the elevation angle of the terminal device by receiving the second notification.

[0070] Next, the network 920 selects a setting from an indexed table to adjust the TA by adjusting the duration of the segments, as shown in 936. This can be performed by any one or more suitable components of the network 920. In this exemplary embodiment, the selection is performed by an access node. For the network 920 to be able to perform the selection, the network must know the elevation angle or position of the terminal device 910, or the distance of the terminal device to the satellite, as described above. If the selection is performed based on position, the setting can be selected from an indexed table based on an estimate of the elevation angle that the network 920 can estimate based on the position of the terminal device 910 and the satellite's ephemeris data. Alternatively, the network 920 obtains an estimated elevation angle as described above and selects a setting to adjust the TA based on the obtained elevation angle estimate. Thus, the setting is applied to the elevation angle of the terminal device. The network 920 then transmits information 946 regarding the selected TA adjustment setting to the terminal device 910.

[0071] In the exemplary embodiments described above, to notify terminal devices of a selected pattern for adjusting TA by defining the duration of segments included in the transmission period, the network may first share an indexed table via broadcast or use terminal device-specific RRC signaling. Next, the network may send a notification regarding the index of the selected setting of segments in the indexed table, i.e., the first column of the indexed table as shown in Table 1. For example, if an indexed table for defining segment durations is sent from the network to terminal devices via RRC, the network may indicate to the terminal devices the index of the selected segment duration in the table via Downlink Control Information DCI for UL Grants. Alternatively, instead of sending the index, the network may send the row of the table corresponding to the selected index. This information may be sent to terminal devices via MAC Control Element (MAC CE) or RRC messages. Also, to improve signaling efficiency, if satellite movement is predictable and terminal device mobility is low, information consisting of segment sizes covering multiple time intervals may be sent, for example, during the first time interval the selected segment is equal to a, during the second time interval the selected segment is equal to b, and so on.

[0072] The exemplary embodiments described above are applicable, for example, to NB-IoT and eMTC. Furthermore, by dividing the transmission period into segments, the exemplary embodiments may have advantages such as limiting interference, as this allows terminal devices to comply with transmission timing requirements. Additionally, since the signaling can refer to an indexed table regarding the length of segments within the transmission period and applicable elevation angles, the signaling is efficient and can be transmitted as broadcast or terminal-specific signaling.

[0073] Figure 10 shows a device 1000, which may be a terminal device or a device contained within a terminal device, according to an exemplary embodiment. The device 1000 comprises a processor 1010, which interprets computer program instructions and processes data. The processor 1010 may include one or more programmable processors. The processor 1010 may include programmable hardware with embedded firmware, and may, alternatively or additionally, include one or more application-specific integrated circuits (ASICs).

[0074] The processor 1010 is connected to the memory 1020. The processor is configured to read and write data to and from the memory 1020. The memory 1020 may comprise one or more memory units. The memory units may be volatile or non-volatile. Note that in some exemplary embodiments, there may be one or more units of non-volatile memory and one or more units of volatile memory, or one or more units of non-volatile memory, or one or more units of volatile memory. Volatile memory is, for example, RAM, DRAM, or SDRAM. Non-volatile memory is, for example, ROM, PROM, EEPROM, flash memory, optical memory, or magnetic memory. In general, memory is sometimes referred to as a non-transient computer-readable medium. The memory 1020 stores computer-readable instructions executed by the processor 1010. For example, non-volatile memory stores computer-readable instructions, and the processor 1010 uses volatile memory for temporary storage of data and / or instructions to execute the instructions.

[0075] Computer-readable instructions may be pre-stored in memory 1020, or alternatively or additionally, may be received by the device via electromagnetic carrier signals and / or copied from a physical entity such as a computer program product. By executing computer-readable instructions, the device 1000 performs the functions described above.

[0076] In the context of this book, “memory” or “computer-readable medium” may be any non-transient medium or means on which instructions used by or in connection with instruction execution systems, apparatus, or devices such as computers are stored, preserved, communicated, propagated, or transported.

[0077] The device 1000 further includes or is connected to an input unit 1030. The input unit 1030 includes one or more interfaces for receiving user input. One or more interfaces may include, for example, one or more motion sensors and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons, and one or more touch detection units. Furthermore, the input unit 1030 may include interfaces to which external devices can be connected.

[0078] The device 1000 also includes an output unit 1040. The output unit includes or is connected to one or more displays capable of rendering visual content, such as light-emitting diodes, LEDs, displays, liquid crystal displays, or LCDs. The output unit 1040 may further include one or more audio outputs. One or more audio outputs may be, for example, loudspeakers or a pair of headphones.

[0079] The device 1000 may further include a connection unit 1050. The connection unit 1050 enables wired and / or wireless connectivity to an external network. The connection unit 1050 may comprise one or more antennas and one or more receivers, which are integrated with the device 1000 or to which the device 1000 may be connected. The connection unit 1050 may comprise an integrated circuit or set of integrated circuits that provide wireless communication functionality to the device 1000. Alternatively, the wireless connectivity may be an application-specific integrated circuit (ASIC).

[0080] It should be noted that the device 1000 may further include various components not shown in Figure 10. These various components may be hardware components and / or software components.

[0081] The apparatus 1100 in Figure 11 may be an access node, or may be included within an access node, and illustrates an exemplary embodiment of the apparatus. The apparatus may be, for example, a circuit or chipset applicable to an access node for implementing the described embodiment. The apparatus 1100 may be an electronic device including one or more electronic circuits. The apparatus 1100 may comprise a communication control circuit 1110, such as at least one processor, and at least one memory 1120 containing computer program code (software) 1122, the at least one memory and the computer program code (software) 1122 together with the at least one processor, which are configured to cause the apparatus 1100 to execute any one of the exemplary embodiments of the access node described above.

[0082] The memory 1120 can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The memory may include a configuration database for storing configuration data. For example, the configuration database may store the current list of adjacent cells and, in some exemplary embodiments, the structure of the frames used by the detected adjacent cells.

[0083] The device 1100 may further include a communication interface 1130 consisting of hardware and / or software for realizing a communication connection according to one or more communication protocols. The communication interface 1130 can provide the device with wireless communication capabilities for communication in a cellular communication system. The communication interface can, for example, provide a wireless interface to a terminal device. The device 1100 may further include another interface leading to a core network, such as a network coordinator device, and / or to an access node in the cellular communication system. The device 1100 may further include a scheduler 1140 configured to allocate resources.

[0084] Although the present disclosure has been described above with reference to the embodiments shown in the attached drawings, it is clear that the disclosure is not limited thereto, and several modifications are possible within the scope of the attached claims. Accordingly, all words and expressions should be interpreted broadly, and they are for illustrative purposes only, not to limit the embodiments. With advances in the art, it will be apparent to those skilled in the art that the concepts of the present invention can be implemented in a variety of ways. Furthermore, it will be apparent to those skilled in the art that the embodiments described can be combined with other embodiments in a variety of ways, although this is not necessary.

Claims

1. A device included in the terminal device (100, 102), wherein the device is Means for obtaining a setting that defines the duration of a segment included in the transmission period for the estimated elevation angle of the terminal device relative to the serving satellite, wherein the segment includes at least one transmission segment and at least one segment for timing advance adjustment. Means for transmitting an uplink transmission to an access node included in a non-terrestrial network during the duration of at least one transmission segment, in accordance with the setting applied to the estimated elevation angle of the terminal device, Means for performing timing advance adjustment after a transmission segment during the period of at least one segment for timing advance adjustment, in accordance with the setting applied to the estimated elevation angle of the terminal device, A device equipped with the following features.

2. The apparatus according to claim 1, wherein the acquired settings are also defined with respect to the azimuth angle of the terminal device with respect to the serving satellite.

3. The apparatus according to claim 1 or 2, further comprising means for estimating the elevation angle of the terminal device with respect to the serving satellite.

4. The apparatus according to claim 3, further comprising means for estimating the elevation angle based on the position of the terminal device obtained from the Global Navigation Satellite System and satellite ephemeris.

5. The apparatus according to claim 3 or 4, further comprising means for transmitting a notification indicating the estimated elevation angle to the access node.

6. The apparatus according to claim 5, wherein the notification includes an index of an indexed table transmitted by the access node.

7. The apparatus according to any one of claims 1 to 6, further comprising means for obtaining from the access node an indexed table including the setting that defines the duration of the segment included in the transmission period for the estimated elevation angle of the terminal device.

8. The apparatus according to claim 7, wherein the aforementioned settings further define timing advance values ​​to be applied in each segment.

9. The apparatus according to claim 7 or 8, further comprising means for obtaining from the access node a notification of the index of the indexed table corresponding to the setting that defines the duration of the segment included in the transmission period, with respect to the estimated elevation angle of the terminal device.

10. A device included in an access node included in a non-terrestrial network, wherein the device is Means for defining an indexed table that defines settings defining the duration of segments included in a transmission period, wherein the segments include at least one transmission segment and at least one segment for timing advance adjustment, and the indexed table includes a range of elevation angles of a terminal device relative to a serving satellite, each having a corresponding setting. Means for obtaining notification regarding an index that defines the setting applied to the elevation angle of the terminal device, A means for scheduling a transmission, wherein the transmission is an uplink transmission, and a scheduling means, A means for receiving the transmission from the terminal device in accordance with the setting applied to the elevation angle of the terminal device, A device equipped with the following features.

11. The apparatus according to claim 10, wherein the setting is also defined with respect to the azimuth angle of the terminal device with respect to the serving satellite.

12. The apparatus according to claim 10 or 11, further comprising means for transmitting the indexed table to the terminal device.

13. The apparatus according to claim 11, further comprising means for estimating the elevation angle and azimuth angle of the terminal device based on the position of the terminal device and satellite ephemeris data.

14. The apparatus according to claim 13, further comprising: means for determining a setting corresponding to the estimated elevation angle and the estimated azimuth angle based on the indexed table; and means for transmitting information regarding the setting corresponding to the estimated elevation angle to the terminal device.

15. The apparatus according to claim 10, further comprising means for obtaining an estimated value of the elevation angle and an estimated value of the azimuth angle from the terminal device, or means for obtaining a notification relating to the index that defines the setting applied to the elevation angle of the terminal device.

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