Method and apparatus for processing system information in non-terrestrial network

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a data transmission rate higher than that of a 4G communication system such as LTE. An operating method of a network device in a non-terrestrial network, according to an embodiment of the present disclosure, may comprise the operations of: receiving a first system information block (SIB), which is transmitted from a central unit (CU) positioned in a terrestrial network and includes configuration information of the non-terrestrial network; generating a second SIB by adding an information element for a satellite positioned in the non-terrestrial network to the first SIB; and broadcasting the second SIB.

Description

Method and device for processing system information in a non-terrestrial network

[0001] The present disclosure relates to a method and apparatus for processing system information in a non-terrestrial network.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of 5G (5th-generation) communication systems, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are expected to evolve into diverse form factors, including augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G."

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes per second (i.e., 1,000 gigabits per second) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster, while the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), beamforming, and multiple antenna transmission technologies such as massive multiple-input and multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience (the next hyper-connected experience) through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive extended reality (Truly Immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through enhanced security and reliability, will find application in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] Meanwhile, research is actively being conducted on Non-Terrestrial Network (NTN) technology, which utilizes satellites in mobile communication systems to provide services to areas where communication services are unavailable (e.g., oceans, polar regions, remote areas, and the air).

[0008] In this disclosure, we propose a method for improving the accuracy of satellite-related information by adjusting the generation time of system information.

[0009] According to one embodiment of the present disclosure, a method for operating a network device in a non-terrestrial network may include: receiving a first system information block (SIB) transmitted from a central unit (CU) located in a terrestrial network and including configuration information for the non-terrestrial network; generating a second SIB by adding an information element for a satellite located in the non-terrestrial network to the first SIB; and broadcasting the second SIB.

[0010] According to one embodiment, the network device may be implemented in at least one of a packet data convergence control (PDCP) layer, a radio link control (RLC) layer, a medium access control (MAC) layer, and a service data adaptation protocol (SDAP) layer within a DU.

[0011] In one embodiment, the network device may be implemented within an on-board computer (OBC) within the satellite located in the non-terrestrial network.

[0012] In one embodiment, the network device may be implemented within a gateway located in the terrestrial network.

[0013] In one embodiment, the network device may include a SIB classifier that identifies the first SIB; a decoder that converts the format of the first SIB into a bit format; a SIB modifier that adds an information element about the satellite located in the non-terrestrial network to the first SIB to generate a second SIB; and an encoder that converts the format of the second SIB into a format transmitted by the CU.

[0014] According to one embodiment, the method of operating the network device may further include receiving a message requesting additional information about the satellite from a user equipment (UE); and transmitting a third SIB including additional information about the satellite to the UE.

[0015] In one embodiment, the additional information about the satellite may include at least one of a satellite power situation, a satellite antenna directionality error average, a satellite attitude error, and a satellite processor utilization rate.

[0016] In one embodiment, the CU located in the terrestrial network may be located within a base station and may have a radio resource control (RRC) layer.

[0017] In one embodiment of the present disclosure, a network device in a non-terrestrial network includes a transceiver; and a control unit. The control unit can receive a first system information block (SIB) transmitted from a central unit (CU) located in a terrestrial network and including configuration information for the non-terrestrial network. The control unit can generate a second SIB by adding an information element for a satellite located in the non-terrestrial network to the first SIB. The control unit can control the broadcasting of the second SIB.

[0018] The method and device according to the embodiment of the present disclosure can prevent performance degradation of a network device due to failure and delay in connection with an external server.

[0019] Additionally, the method and device according to the embodiment of the present disclosure can improve the accuracy of satellite-related information by reducing the difference between the time of generation and the time of broadcasting of system information.

[0020] Figure 1 shows an example of a method for operating a satellite cell in non-terrestrial network communication.

[0021] Figure 2 shows another example of a satellite cell operation method in non-terrestrial network communication.

[0022] FIG. 3 illustrates the structure of a communication system in which a mobile communication network and a satellite network are integrated according to one embodiment of the present disclosure.

[0023] FIG. 4A illustrates an example of the structure of a communication system in which a mobile communication network and a satellite network are operated according to one embodiment of the present disclosure.

[0024] FIG. 4b illustrates another example of the structure of a communication system in which a mobile communication network and a satellite network are operated according to one embodiment of the present disclosure.

[0025] FIG. 5 illustrates various examples of a communication system including a non-terrestrial network according to one embodiment of the present disclosure.

[0026] FIG. 6 illustrates a process of generating and transmitting a SIB based on satellite-related information according to one embodiment of the present disclosure.

[0027] FIG. 7 illustrates a SIB IE insertion function for generating a SIB according to one embodiment of the present disclosure.

[0028] FIG. 8 illustrates a structure in which a SIB IE insertion function is implemented in a communication layer of a DU according to one embodiment of the present disclosure.

[0029] FIG. 9 illustrates a structure in which a SIB IE insertion function is implemented within an OBC of a satellite according to one embodiment of the present disclosure.

[0030] FIG. 10 illustrates a structure in which a SIB IE insertion function is implemented in a gateway according to one embodiment of the present disclosure.

[0031] FIG. 11 illustrates a process in which a gateway generates a SIB and satellite information is added from a satellite according to one embodiment of the present disclosure.

[0032] FIG. 12a illustrates a process in which a UE requests additional satellite information from a base station according to one embodiment of the present disclosure.

[0033] FIG. 12b illustrates a process in which a UE requests additional satellite information from a satellite according to one embodiment of the present disclosure.

[0034] FIG. 13 illustrates the structure of a UE according to one embodiment of the present disclosure.

[0035] FIG. 14 illustrates the structure of a base station according to one embodiment of the present disclosure.

[0036] FIG. 15 illustrates the structure of a satellite according to one embodiment of the present disclosure.

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0038] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0039] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0040] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined solely by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0041] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0042] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0043] Here, the term '~ unit' used in this embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

[0044] The present disclosure relates to Non-Terrestrial Network (NTN) technology, which utilizes satellites in mobile communication systems to provide services in areas where communication services are unavailable (e.g., oceans, polar regions, remote areas, or the air). Not only 5G, which has adopted NTN technology as a standard, but also 6G, which is expected to be commercialized in 2030, may include NTN technology. Active research is being conducted on mobile communication systems, satellite systems, and / or systems combining mobile communication and satellite systems to support NTN.

[0045] NTN is a technology that utilizes satellites as relays to establish communication coverage in areas where base stations for mobile communications are physically or economically impractical. Satellites available for NTN include Geostationary Earth Orbit (GEO), Medium Earth Orbit (MEO), and Low Earth Orbit (LEO) satellites, depending on their altitude. Due to the correlation between satellite altitude and communication latency, LEO satellites can guarantee relatively low latency when used in NTN.

[0046] NTN using LEO satellites has the advantage of low latency due to the short radio round trip time because it exists at a low altitude (200 km to 2000 km) compared to other satellites (e.g. GEO satellites or MEO satellites). However, because it is very fast compared to other satellites (approximately 7.56 km / s at an altitude of 600 km), it has the characteristic of constantly changing frequency / time synchronization in non-mobile terminals or satellite antennas. In NTN using LEO satellites, the need for a technology that more accurately calculates and compensates for the changes in frequency / time synchronization due to the mobility of LEO satellites is gradually increasing.

[0047] Meanwhile, satellites can be classified based on their functions in NTN. In NTN, satellites can be classified as 1) transparent payload; or 2) regenerative payload; based on their functions. Transparent payload refers to a satellite that is equipped only with the functions of signal amplification and frequency conversion, and transmits the signal to the ground without processing, like a reflector / repeater. Transparent payload satellites do not support the functions that can perform the functions of a base station, such as a distributed unit (DU) or central unit (CU). Regenerative payload, also called On-Board Processing (OBP) payload, is equipped with a processor capable of processing, allowing the satellite to perform the functions of a base station, such as a DU or CU.

[0048] One embodiment of the present disclosure may be applicable to a transparent payload satellite. Furthermore, one embodiment of the present disclosure may be applicable to a regenerative payload in which only the DU is mounted on the satellite and the CU exists on the ground. Furthermore, one embodiment of the present disclosure may be applicable to a regenerative payload in which the CU exists on the ground and the DU exists on the satellite.

[0049] Meanwhile, 3GPP NTN has standardized the ability for terminals (or UEs) to self-correct frequency and time synchronization before connecting to a base station via satellite. For a terminal to correct frequency and time synchronization, it requires information about its location and mobility, as well as the location and mobility of the satellite. Accordingly, the NTN standard allows terminals to utilize the Global Navigation Satellite System (GNSS) to measure their mobility and location information, and to use the measurement results for frequency and time synchronization correction and terminal mobility management. Furthermore, terminals can obtain satellite location and mobility information through broadcast messages transmitted from base stations connected to satellites.

[0050] According to one embodiment, a broadcast message transmitted by a base station to a terminal may include at least one of information related to a position of a satellite, a velocity of the satellite, orbital information of the satellite, and a satellite cell formed by the satellite.

[0051] 3GPP NR NTN defines System Information Block 19 (SIB19) as the above broadcast message. The SIB19 message may include Information Elements (IE) regarding orbital information of a satellite connected to a base station transmitting the SIB19 message, position information of the satellite, and velocity information of the satellite. The SIB19 message may include information related to satellite cell operation (e.g., satellite cell center position and diameter, surrounding satellite cell information).

[0052] According to one embodiment, the SIB19 message may be structured as follows.

[0053]

[0054] According to one embodiment, the NTN-config included in the SIB19 message may be configured as follows.

[0055]

[0056] In one embodiment, SIB19 may be generated in the RRC layer of the CU and transmitted to the PHY layer via the Transparent Mode (TM) of the RLC and the transparent MAC of the MAC layer. The TM and transparent MAC functions are transmitted without adding additional processes or headers, so SIB19 may be transmitted to the PHY layer via the PDCP layer, the RLC layer, and the MAC layer. After this, the PHY layer may transmit the received SIB according to the configured cycle.

[0057] NR NTN can classify satellite cell operation methods into 1) earth fixed cell, 2) quasi-earth fixed cell, and 3) earth moving cell. An earth fixed cell is a method of forming a stationary satellite cell in a certain area through a satellite, and is a cell formed by a GEO satellite that has the same orbital period as the Earth's rotation period. Quasi-earth fixed cell and earth moving 1cell are classifications for two methods when forming a satellite cell by a MEO satellite and / or LEO satellite whose orbital period is not the same as the Earth's rotation period.

[0058] Figure 1 illustrates an example of a satellite cell operation method in non-terrestrial network communication. Referring to Figure 1, a satellite cell operation method using a quasi-earth fixed cell is illustrated.

[0059] Quasi-earth fixed cells are a method of forming satellite cells in a fixed area on the Earth's surface. However, unlike GEO satellites, which do not move relative to the Earth's surface, which can form a fixed area 24 hours a day, LEO and MEO satellites move relative to the Earth's surface, so they cannot continuously form cells in a fixed area. In this case, the antenna of the beam that forms the satellite's cell rotates to form a cell in a fixed area even if the satellite moves relative to the ground. If a satellite cell exists at a location greater than the maximum antenna rotation angle due to the satellite's movement and the satellite cannot form a cell, another satellite in the vicinity can take over and form a cell in that location.

[0060] Referring to FIG. 1, at time t1, an NTN device (NTN vehicle) can form satellite coverage in a certain area of ​​the Earth's surface. The satellite coverage can include a plurality of cells in fixed positions.

[0061] An NTN device (NTN vehicle) can move and form satellite coverage in a certain area of ​​the Earth's surface at time t2. The satellite coverage can include multiple cells in fixed positions.

[0062] In one embodiment, even if the NTN vehicle moves, the NTN vehicle can implement the same Quasi-earth fixed cell at time t1 and time t2 via a steerable spot beam.

[0063] In one embodiment, a maximum elevation angle may be set based on the location of the NTN vehicle and the center location of satellite coverage. For example, a minimum elevation angle may be set based on the location of the NTN vehicle and the edge location of satellite coverage.

[0064] Figure 2 illustrates another example of a satellite cell operation method in non-terrestrial network communication. Referring to Figure 2, a satellite cell operation method using an Earth moving cell is illustrated.

[0065] Earth moving cell is an operating method in which a satellite cell moves along with the movement of the satellite when the antenna forming the cell of the MEO satellite and / or LEO satellite cannot rotate.

[0066] Referring to FIG. 2, as an NTN device (NTN vehicle) moves from time t1 to time t2, satellite coverage may move corresponding to the changing position of the NTN device (NTN vehicle). The satellite coverage may include a plurality of cells (Cells in fixed positions) at the moving position.

[0067] In one embodiment, as the NTN device moves, the NTN device can implement different Earth moving cells at times t1 and t2 via a non-steerable spot beam. In one embodiment, as the NTN device moves, the position of the Earth moving cell can move correspondingly.

[0068] For example, a maximum elevation angle may be set based on the position of the NTN vehicle and the center position of satellite coverage. For example, a minimum elevation angle may be set based on the position of the NTN vehicle and the edge position of satellite coverage.

[0069] FIG. 3 illustrates the structure of a communication system in which a mobile communication network and a satellite network are integrated according to one embodiment of the present disclosure.

[0070] Referring to FIG. 3, the communication system may include a satellite access network (310), a first UE (320) connected to and communicating with the satellite access network (310), a terrestrial access network (330), a second UE (340) connected to and communicating with the terrestrial access network (330), a data network (350), and a core network (360).

[0071] The satellite access network (310) may include at least one satellite and at least one gateway. The terrestrial access network (330) may include at least one base station. The data network (350) may include at least one server for transmitting and receiving data. The core network (360) may be connected to each of the satellite access network (310), the terrestrial access network (330), and the data network (350) to control network communications.

[0072] In one embodiment, at least one of the satellite access network (310), the terrestrial access network (330), the data network (350), and the core network (360) may operate according to the 3GPP NR specifications.

[0073] The NTN may be configured by combining a satellite access network (310) and a terrestrial access network (330). A first UE (320) and / or a second UE (340) may utilize both the satellite access network (310) and the terrestrial access network (330) to communicate with a server within a data network (350). A core network (360) may manage (or control) at least one base station within the terrestrial access network (330) and at least one satellite within the satellite access network (310).

[0074] FIG. 4A illustrates an example of a communication system in which a mobile communication network and a satellite network are operated according to an embodiment of the present disclosure. FIG. 4A illustrates a structure of a communication system in a regenerative payload. Referring to FIG. 4A, a communication system supporting a regenerative payload may include a Satellite Transport Network (410) including a distributed unit (DU), a central unit (CU) (420), a Core Network (430) including at least one network function (NF), at least one UE (440) connected to the Satellite Transport Network (410), a data network (450) connected to the Core Network (430), an external NTN management system (460), and a cellular network management system (465).

[0075] A satellite transmission network (410) including a DU can communicate with at least one UE (440), an external NTN management system (460), and a cellular network management system (465) to transmit and receive data and / or messages. A CU (420) and / or a core network (430) can communicate with the cellular network management system (465) to transmit and receive data and / or messages.

[0076] FIG. 4b illustrates another example of a communication system in which a mobile communication network and a satellite network operate according to one embodiment of the present disclosure. FIG. 4b illustrates the structure of the communication system in a transparent payload.

[0077] Referring to FIG. 4b, a communication system supporting transparent payload may include a Satellite Transport Network (410), a DU (415), a CU (420), a core network (430) including at least one network function (NF), at least one UE (440) connected to the Satellite Transport Network (410), a data network (450) connected to the core network (430), an external NTN management system (460), and a cellular network management system (465).

[0078] A DU (415) implemented outside of a satellite transmission network (410) can communicate with at least one of a CU (420), at least one UE (440), an external NTN management system (460), and a cellular network management system (465) to transmit and receive data and / or messages. The CU (420) and / or the core network (430) can communicate with the cellular network management system (465) to transmit and receive data and / or messages.

[0079] This disclosure primarily targets cases where satellite communication networks and mobile communication networks are operated separately and cooperate with each other.

[0080] Terrestrial networks (TNs) allow communication from terminals (or UEs) to the core network (CN) via a cellular network installed and managed by a telecommunications company. These networks can be managed by telecommunications companies' servers, which can be designed according to 3GPP standards.

[0081] In the case of NTN, some sections of the communication path from the terminal to the CN may be on a network other than the carrier's network. For example, in the case of a transparent NTN payload, a Network Entity (NE), such as an NTN gateway and / or NTN vehicle, may exist between the base station and the terminal. In one embodiment, the NTN NE may be managed by the carrier's server, but may also be managed by a separate system that installs and manages the NE, not the carrier.

[0082] Unlike terrestrial networks (TNs), which can manage all connections between terminals and the CN, NTNs cannot be managed by the CN in some sections. In these cases, services can be provided through integration between the management system that manages certain sections and the mobile network system.

[0083] In one embodiment, a SIB (e.g., SIB19) for a satellite is provided to operate NTN, and in order to generate the SIB message, a CU (Centralized Unit) that generates the message requires satellite-related information (e.g., satellite ID, satellite position, satellite velocity, etc.) in addition to mobile communication network-related information.

[0084] In one embodiment, a RAN CU responsible for a cell of an NTN may store satellite-related status and satellite information forming the cell responsible for the CU, or may obtain satellite status changes through information exchange with an external satellite server. In one embodiment, the CU may be equipped with a storage function for satellite orbital information and an orbit calculation function. As the number of satellites increases, additional processing may be consumed due to the storage space for orbital information or the complexity of the orbit calculation function.

[0085] If the satellites forming the cell managed by the CU are managed according to a pre-determined schedule (e.g., satellite 1 forms the cell from 12:01 to 12:05, satellite 2 forms the cell from 12:05 to 12:10), the satellites forming the cell managed by the CU can be predicted and information about the corresponding satellites can be calculated and acquired. In this case, the CU needs to periodically connect with the satellite network management server to confirm whether it is operating according to the set schedule.

[0086] In the case of satellite networks, which manage the network dynamically through multiple satellites to ensure efficient operation, there is no fixed schedule. Instead, the satellite cell configuration structure can be dynamically changed based on network conditions (e.g., the number of users connected to the satellite, satellite power remaining, satellite processor performance, etc.). In this operation method, for a CU to be aware of changes in the satellites forming the cell it is responsible for, it must closely exchange information with the satellite network.

[0087] However, when CU creates SIB, the following disadvantages may exist:

[0088] 1) Performance degradation of NTN due to phenomena occurring during information exchange with the satellite network server;

[0089] When a CU periodically or as needed exchanges satellite-related information with a satellite network server, delays and failures may occur in the information exchange interface. This delay may delay the generation of the SIB required to access and maintain the satellite network, potentially degrading NTN performance.

[0090] 2) Additional processing capabilities required for satellite orbit information calculations in CU and delays resulting from such calculations;

[0091] If the CU possesses orbital information capable of calculating satellite orbits and satellite network operation schedules, it calculates satellite position and velocity information based on the satellite orbital information and inserts this information into the SIB. In this case, as the number of satellites increases and the satellites forming a cell change cycle shorten, the computational overhead imposed on the CU increases. This requires the installation of more processors on the CU.

[0092] 3) Performance degradation due to errors with actual satellite information caused by the difference between the time of generation of SIB generated by CU and the time of broadcast by DU;

[0093] The satellite information included in the SIB generated by the CU may include satellite position / velocity information at the time the SIB was generated. Since the CU that generates the SIB is on the ground and the DU that broadcasts the SIB is on a satellite connected to the CU through the NTN gateway, there is a difference between the actual generation time and the broadcast time. In the case of a satellite network that uses an inter-satellite link (ISL), the distance and time difference between the DU and the CU may be larger. This time difference causes an error between the actual satellite position / velocity and the satellite position / velocity included in the SIB, and the accuracy of various functions within the NTN that use the information (e.g., Doppler effect correction, Timing Advance calculation, etc.) may decrease, resulting in deterioration of the NTN performance.

[0094] This disclosure proposes a method in which a CU independently generates a portion of a SIB without interacting with an external satellite server, and then completes the satellite information with another network entity. This method generates SIBs without interacting with a satellite network server, thereby preventing performance degradation in the NTN.

[0095] FIG. 5 illustrates various examples of a communication system including a non-terrestrial network according to one embodiment of the present disclosure.

[0096] Referring to (a) to (d) of FIG. 5, the communication system may include a satellite (or NTN vehicle) (any one of 510, 512, 514, 516), a Distributed Unit (DU) in charge of an NTN cell (any one of 520, 522, 524, 526), ​​an NTN gateway (any one of 530, 532, 534, 536), and a Central Unit (CU) (any one of 540, 542, 544, 546).

[0097] The link between a satellite (any of 510, 512, 514, 516) and an NTN gateway (any of 530, 532, 534, 536) may be referred to as a feeder link. The link between satellites (510, 512, 514, 516) may be referred to as an Inter-Satellite Link (ISL).

[0098] In the present disclosure, the protocol stack is the same as the NR NTN protocol and may be composed of a PHY (Physical) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Control) layer, an RRC (Radio Resource Control) layer, and an SDAP (Service Data Adaptation Protocol) layer.

[0099] In the NTN illustrated in (a) of FIG. 5, the DU (520) is located within the satellite (510) and may include a PDCP layer, an RLC layer, a MAC layer, a PHY layer, and an SDAP layer. The CU (540) is located within the ground (or base station) and may include an RRC layer. The CU (540) may transmit information and / or messages to the gateway (530) via the RRC layer, and the gateway (530) may transmit the information and / or messages to the satellite (510).

[0100] In the NTN illustrated in (b) of FIG. 5, the DU (522) is located within the satellite (512) and may include an RLC layer, a MAC layer, a PHY layer, and an SDAP layer. The CU (542) is located within the ground (or base station) and may include a PDCP layer and an RRC layer. The CU (542) transmits information and / or messages to the gateway (532) via the PDCP layer and the RRRC layer, and the gateway (532) may transmit the information and / or messages to the satellite (512).

[0101] In the NTN illustrated in (c) of FIG. 5, the DU (520) may be located within the first satellite (514) and may include a PDCP layer, an RLC layer, a MAC layer, a PHY layer, and an SDAP layer. The first satellite (514) may perform inter-satellite communication with the second satellite (515). The CU (544) may be located within the ground (or base station) and may include an RRC layer. The CU (544) may transmit information and / or messages to the gateway (534) via the RRC layer, and the gateway (540) may transmit the information and / or messages to the second satellite (515). The second satellite (515) may transmit the information and / or messages to the first satellite (514).

[0102] In the NTN illustrated in (d) of FIG. 5, the DU (526) may be located within the first satellite (516) and may include an RLC layer, a MAC layer, a PHY layer, and an SDAP layer. The first satellite (516) may perform inter-satellite communication with the second satellite (517). The CU (546) may be located within the ground (or base station) and may include a PDCP layer and an RRC layer. The CU (546) may transmit information and / or messages to the gateway (536) through the PDCP layer and the RRRC layer, and the gateway (536) may transmit the information and / or messages to the second satellite (517). The second satellite (517) may transmit the information and / or messages to the first satellite (516).

[0103] In the present disclosure, CUs (540, 542, 544, 546) may exist on the ground together with gateways (530, 532, 534, 536), and DUs (520, 522, 524, 526) may exist on a satellite. An RRC layer may be essentially present in CUs (540, 542, 544, 546), and a PHY layer may be essentially present in DUs (520, 522, 524, 526). According to one embodiment, at least one of an RLC layer, a MAC layer, and a PDCP layer may be present in CUs (540, 542, 544, 546) or DUs (520, 522, 524, 526). In one embodiment, the RRC layer may be present simultaneously in CUs (540, 542, 544, 546) and DUs (520, 522, 524, 526).

[0104] The present disclosure primarily targets a case in which CUs (540, 542, 544, 546) exist on the ground and DUs (520, 522, 524, 526) exist on a satellite in an NTN using a regenerative payload. In one embodiment, CUs (540, 542, 544, 546) and gateways (530, 532, 534, 536) may be connected via a terrestrial wired network. In one embodiment, gateways (530, 532, 534, 536) and DUs (520, 522, 524, 526) may be connected via a feeder link when ISL is not used, or via a feeder link and ISL when ISL is used.

[0105] FIG. 6 illustrates a process of generating and transmitting a SIB based on satellite-related information according to one embodiment of the present disclosure.

[0106] Referring to (a) of FIG. 6, the communication system may include a terminal (610), a satellite (614) where a DU (612) is located, a gateway (616), a CU (618), and a satellite network server (620).

[0107] The CU (618) can receive information on whether a satellite forming a satellite cell has changed and / or information related to a changed satellite from the satellite network server (620). If satellite orbit information exists in the CU (618), the CU (618) can only receive information on whether a satellite has changed from the satellite network server (620). Thereafter, the CU (618) can generate an NTN SIB based on a generation period for the NTN SIB (e.g., SIB19) and transmit the generated NTN SIB to the DU (612). The DU (612) can receive the NTN SIB transmitted from the CU (618) through the gateway (616). The DU (612) can broadcast the NTN SIB based on a repetition value, which is a constant period, through the PHY layer. Afterwards, the terminal (610) can receive the NTN SIB broadcasted by the DU (612).

[0108] Referring to (b) of FIG. 6, the communication system may include a terminal (630), a satellite (634) where a DU (632) is located, a gateway (636), and a CU (638).

[0109] The CU (638) can generate an NTN SIB composed of information other than satellite-related information (or IE) based on a generation period and transmit the generated NTN SIB to the DU (632). The DU (632) can receive an NTN SIB that does not include satellite-related information (or IE) transmitted by the CU (638) through the gateway (636). The DU (632) can generate satellite-related information (or IE) based on information acquired from the satellite (634) and add the satellite-related information (or IE) to the NTN SIB. The DU (632) can broadcast the NTN SIB based on a repetition value, which is a constant period, through the PHY layer. Thereafter, the terminal (610) can receive the NTN SIB broadcast by the DU (612).

[0110] In the present disclosure, an additional writing method may be required that implies that some of the IEs in the NTN SIB are generated in the DU (632) rather than the CU (638). According to one embodiment, the SIB is written in the Abstract Syntax Notation One (ASN.1) grammar, and the grammar cannot newly define variables for the above-mentioned additional writing method. Therefore, when writing the SIB based on the ASN.1 grammar, a writing method that implies that some of the IEs in the NTN SIB are generated in the DU can be performed through the two examples below. Although the ASN.1 grammar is described as an example of a grammar for writing the SIB in the present disclosure, the technical idea of ​​the present disclosure is not limited thereto, and the SIB can be generated based on at least one various grammar.

[0111] The first example method is to define as 'NULL' the IEs that should be written in a location other than CU (638) among the IEs included in NTN SIB. In DU (632) other than CU (638), the parts of the IEs included in SIB written with NULL values ​​are determined as IEs that DU (632) should additionally write, and DU (632) can write the IEs with the NULL values ​​according to the format of the IEs. All IEs written with NULL values ​​in SIB may be information related to the satellite network. According to one embodiment, DU (632) can directly access the corresponding IE values ​​in satellite (634) and write the corresponding IEs. According to one embodiment, gateway (636) can access the information stored in the database of gateway (636) and write the corresponding IEs.

[0112] An example of a SIB written using the first example method is as follows.

[0113] [NTN SIB (e.g., SIB19) information element]

[0114]

[0115] [NTN-Config information element]

[0116]

[0117] [EphemerisInfo information element]

[0118]

[0119] The second example method is to reorganize the IEs included in the NTN SIB and define the IEs that should be written in a location other than the CU (638) as new fields. The fields are written according to rules that are standardized or technically predetermined, and the DU (632) can write the fields on its own even if they do not exist. The drawing below is an example in which NTN-PayloadInfo is redefined as a field to be written in the DU (632) rather than the CU (638). An example of an NTN SIB written using the second example method is shown in the drawing below.

[0120] [SIB generated by RRC in CU]

[0121]

[0122] [SIB generated in DU]

[0123]

[0124] FIG. 7 illustrates a SIB IE insertion function for generating a SIB according to one embodiment of the present disclosure.

[0125] Referring to FIG. 7, the NTN SIB IE insertion function (700) may include an NTN SIB classifier (710), an ASN.1 decoder (720), an NTN SIB modifier (730), and an ASN.1 encoder (740). According to one embodiment, the NTN SIB IE insertion function (700) may be implemented in hardware and / or software and included and / or installed within a specific device.

[0126] NTN SIB can be encoded in bit form and transmitted after being written in ASN.1 grammar according to the format set by RRC. Layers other than RRC may not be able to read or modify the IEs in NTN SIB. In one embodiment, in the present disclosure where NTN SIB needs to be modified in the middle, an 'NTN SIB IE insertion function' capable of providing such a function needs to be present in the location where the function is performed.

[0127] The NTN SIB classifier (710) can determine whether the SIB is an NTN-related SIB. The ASN.1 decoder (720) can convert a format expressed in ASN.1 grammar into a bit format. The NTN SIB modifier (730) can obtain an NTN SIB and modify and / or add information of at least one IE (e.g., a satellite-related IE) in the SIB. The ASN.1 encoder (740) can convert a bit format representation into an ASN.1 grammar format.

[0128] According to one embodiment, the NTN SIB IE insertion function (700) may be implemented within a network entity between a satellite DU, a ground CU, and / or a satellite DU and a ground CU. In the following embodiments, the NTN SIB IE insertion function (700) is described and diagrammed in 1) the case where it exists in the satellite communication layer (MAC, RLC, PDCP, RRC), 2) the case where it exists in the satellite OBC (On-Board Computing), and 3) the case where it exists in the NTN gateway.

[0129] FIG. 8 illustrates a structure in which a SIB IE insertion function is implemented in a communication layer of a DU according to one embodiment of the present disclosure.

[0130] Referring to FIG. 8, a communication system may include a terminal (810), a satellite (830) having a DU (820), a gateway (840), and a CU (850). The CU (850) may generate an NTN SIB that does not include satellite information (or satellite-related IE). The CU (850) may transmit the NTN SIB that does not include satellite information (or satellite-related IE) to the DU (820) via the gateway (840).

[0131] The satellite (830) may include a Satellite On-board Computer (OBC) (821). The DU (820) may include an RRC layer (822), a PDCP layer (823), an RLC layer (824), a MAC layer (825), and a PHY layer (826). According to one embodiment, the SIB IE insertion function (860) may be implemented in at least one of the PDCP layer (823), the RLC layer (824), and the MAC layer (825) within the DU (820).

[0132] In the structure of the communication protocol, the PDCP layer (823), RLC layer (824), and MAC layer (825) above the PHY layer (826) are implemented in a form that passes through without adding or processing a header, and the NTN SIB IE insertion function (860) can be located in any of the PDCP layer (823), the RLC layer (824), and the MAC layer (825). According to one embodiment, if there is a split RRC in which the DU (820) is responsible for some functions of the RRC, the NTN SIB IE insertion function (860) can perform the corresponding function in the RRC layer existing in the DU (820). In this case, if the split RRC has the same elements among the components that constitute the NTN SIB IE insertion function (860), some duplicate elements within the corresponding function may not exist.

[0133] The NTN SIB IE insertion function (860) can write satellite information (or satellite-related IE) and generate an NTN SIB including the satellite information (or satellite-related IE). The NTN SIB IE insertion function (860) can include an NTN SIB classifier (862), an ASN.1 decoder (864), an NTN SIB modifier (866), and an ASN.1 encoder (868). According to one embodiment, the NTN SIB IE insertion function (860) can be implemented in hardware and / or software and included and / or installed in the DU (820).

[0134] The NTN SIB classifier (862) can determine whether the SIB is an NTN-related SIB. The ASN.1 decoder (864) can convert a format expressed in ASN.1 grammar into a bit format. The NTN SIB modifier (866) can obtain an NTN SIB and modify and / or add information of at least one IE (e.g., a satellite-related IE) in the NTN SIB. The ASN.1 encoder (868) can convert a bit format representation into an ASN.1 grammar format.

[0135] The CU (860) performs NTN SIB (e.g., SIB19) writing, and in this process, the writing can be completed without writing IEs that are related to the satellite network and can be written through connection with the satellite network. The NTN SIB without satellite network-related information can be transmitted to the satellite (830) via the gateway (840). The satellite (830) can transmit the NTN SIB without satellite network-related information to the DU (820) having the NTN protocol stack.

[0136] During the process of passing through the layer of DU (820), the NTN SIB can add satellite network related information to the NTN SIB in which no satellite network related information exists and transmit it to the PHY layer (826) by the NTN SIB IE insertion function (860). The PHY layer (826) can finally receive the NTN SIB containing all information from the upper layer and broadcast the NTN SIB at a specified interval.

[0137] FIG. 9 illustrates a structure in which an NTN SIB IE insertion function is implemented within an OBC of a satellite according to one embodiment of the present disclosure.

[0138] Referring to FIG. 9, a communication system may include a terminal (910), a satellite (930) having a DU (920), a gateway (940), and a CU (950). The CU (950) may generate an NTN SIB that does not include satellite information (or satellite-related IE). The CU (950) may transmit the NTN SIB that does not include satellite information (or satellite-related IE) to the DU (920) via the gateway (940).

[0139] A satellite (930) may include a Satellite On-board Computer (OBC) (931). A DU (920) within the satellite (930) may include a PDCP layer (932), an RLC layer (933), a MAC layer (934), and a PHY layer (935). In one embodiment, an NTN SIB IE insertion function (960) may be implemented within the OBC (931).

[0140] The NTN SIB IE insertion function (960) can write satellite information (or satellite-related IE) and generate an NTN SIB including the satellite information (or satellite-related IE). The NTN SIB IE insertion function (960) can include an NTN SIB classifier (962), an ASN.1 decoder (964), an NTN SIB modifier (966), and an ASN.1 encoder (968).

[0141] In the feeder link between the gateway (940) and the satellite (930), transmission may be performed via a satellite protocol stack introduced by the satellite network. In this case, packets generated by the CU (950) are encapsulated and transmitted by the satellite protocol stack in the gateway (940), and the satellite (930) may decapsulate the received encapsulated packets through the OBC (931) and transmit them to the NTN protocol stack. After decapsulation is performed in the OBC (931), an NTN SIB IE insertion function (960) may exist within the OBC (931).

[0142] The CU (950) performs NTN SIB (e.g., NR NTN SIB) creation, and in this process, IEs that are related to the satellite network and can be created through linkage with the satellite network can be completed without being created. An NTN SIB without satellite network-related information can be transmitted to the OBC (931) of the satellite (930) through the gateway (940). After performing decapsulation, the OBC (931) can add satellite network-related information to the NTN SIB without satellite network-related information through the NTN SIB IE insertion function (960) and transmit the NTN SIB to the PHY layer (935). The PHY layer (935) can finally receive the NTN SIB containing all information from the upper layer and broadcast the NTN SIB at a specified interval.

[0143] FIG. 10 illustrates a structure in which a SIB IE insertion function is implemented in a gateway according to one embodiment of the present disclosure.

[0144] Referring to FIG. 10, a communication system may include a terminal (1010), a satellite (1030) having a DU (1020), a gateway (1040), and a CU (1050). The CU (1050) may generate an NTN SIB that does not include satellite information (or satellite-related IE). The CU (1050) may transmit the NTN SIB that does not include satellite information (or satellite-related IE) to the DU (1020) via the gateway (1040).

[0145] The NTN SIB IE insertion function (1060) may be implemented within the gateway (1040). The NTN SIB IE insertion function (1060) may create satellite information (or satellite-related IE) and generate an NTN SIB including the satellite information (or satellite-related IE). The NTN SIB IE insertion function (1060) may include an NTN SIB classifier (1062), an ASN.1 decoder (1064), an NTN SIB modifier (1066), and an ASN.1 encoder (1068).

[0146] Since the gateway (1040) sets up and / or manages multiple satellites and feeder links, satellite orbit and satellite position related information can always be stored within the gateway (1040). If the gateway (1040) has an NTN SIB IE insertion function (1060), the NTN SIB IE insertion function (1060) can exist at a stage prior to encapsulating the packet into the satellite protocol stack.

[0147] The CU (1050) performs NTN SIB (e.g., NR SIB19) writing, and in this process, IEs that are related to the satellite network and can be written through connection with the satellite network can be written without being written. An NTN SIB without satellite network-related information can be transmitted to the gateway (1040) to be transmitted to the satellite (1030). The NTN SIB received by the gateway (1040) can have satellite network-related information additionally written by the NTN SIB IE insertion function (1060) before being encapsulated into the satellite protocol stack, and can be transmitted to the satellite (1030). The PHY layer of the satellite (1030) can finally receive the NTN SIB containing all information from the upper layer and broadcast the NTN SIB at a specified interval.

[0148] FIG. 11 illustrates a process in which a gateway generates a SIB and satellite information is added from a satellite according to one embodiment of the present disclosure.

[0149] Referring to FIG. 11, a communication system may include a terminal (1110), a satellite (1130) having a DU (1120), a gateway (1140), and a CU (1150). The CU (1150) may generate an NTN SIB that does not include satellite information (or satellite-related IE). The CU (1150) may transmit the NTN SIB that does not include satellite information (or satellite-related IE) to the DU (1120) via the gateway (1140).

[0150] If a NTN SIB insertion function exists in a satellite (1130) and the function is performed, various status information stored in the satellite may be additionally inserted into the NTN SIB in addition to satellite orbit and position information. In one embodiment, information that may be additionally inserted into the NTN SIB may be information stored in a database within the satellite OBC, and may be inserted when specifying the IE format.

[0151] According to one embodiment, information that can be additionally inserted into the NTN SIB may include at least one of satellite power status, the number of terminals connected to the satellite, satellite processor utilization, and satellite beam scheduling information. Methods for inserting the information may include 1) insertion through additional IE pre-designation in the NTN SIB (e.g., SIB19) depending on the NTN SIB transmission and request method; or 2) designating an additional SIB in addition to the NTN SIB and inserting an additional IE in the additional SIB. The reason for classifying the two methods above is that there is a difference in the method of transmitting the SIB in the current system.

[0152] SIB transmission methods are classified into periodic SI and on-demand SI. Periodic SI is a method in which a base station continuously transmits SIBs at regular intervals, and on-demand SI is a method in which a requested SIB is transmitted to a terminal when the terminal transmits a signal requesting an SIB to the base station. Periodic SI is used for SIBs that are essential for network access, and non-essential SIBs are transmitted using the on-demand SI method to reduce the transmission overhead of transmitting the SIBs. In one embodiment, since NTN SIBs (e.g., SIB19) are essential for NTN access, only the periodic SI method may be supported, not allowing on-demand SI.

[0153] FIG. 12a illustrates a process in which a UE requests additional satellite information from a base station according to one embodiment of the present disclosure.

[0154] Referring to FIG. 12A, in operation 1201, the UE (1210) may receive a master information block (MIB) from the RAN (1220). In operation 1203, the UE (1210) may receive a system information block 1 (SIB) from the RAN (1220). In operation 1205, the RAN (1220) may transmit an NTN SIB including a satellite information indicator to the UE (1210). According to one embodiment, the satellite information indicator may indicate that there is additional satellite information in addition to the satellite-related IEs included in the NTN SIB. In operation 1207, the UE (1210) may transmit a System Information Request message to the RAN (1220) to request additional satellite information. In operation 1209, the RAN (1220) may transmit a SIB_SI containing additional information of the satellite to the UE (1210).

[0155] In addition to a method for inserting additional information into a SIB using a periodic SI method, the present disclosure proposes a method for transmitting additional satellite information in an on-demand SI manner through a separate SIB rather than an existing SIB (e.g., SIB19). When inserting satellite-related additional information into an existing SIB (e.g., SIB19), an indicator indicating the presence of the additional information is unnecessary. However, when transmitting satellite additional information through a separate SIB, an identifier indicating the presence of a SIB containing the satellite additional information is required. The identifier may be located in SIB1 and a SystemInformation message, or in an existing NTN SIB (SIB19).

[0156] FIG. 12b illustrates a process in which a UE requests additional satellite information from a satellite according to one embodiment of the present disclosure.

[0157] Referring to FIG. 12B, in operation 1211, the UE (1210) may receive a master information block (MIB) from the RAN (1220). In operation 1213, the UE (1210) may receive a system information block 1 (SIB) from the RAN (1220). In operation 1215, the satellite (1230) may transmit an NTN SIB including a satellite information indicator to the UE (1210). The satellite information indicator may indicate that there is additional satellite information in addition to the satellite-related IE included in the NTN SIB. In operation 1207, the UE (1210) may transmit a System Information Request message to the satellite (1230) to request additional satellite information. In operation 1209, the satellite (1230) may transmit an SIB_SI including additional information of the satellite to the UE (1210).

[0158] FIG. 13 illustrates the structure of a UE according to one embodiment of the present disclosure.

[0159] The UE (or terminal) described with reference to FIGS. 1 to 12b may correspond to the UE of FIG. 13. Referring to FIG. 13, the UE may be composed of a transceiver unit (1310), a memory (1320), and a control unit (1330).

[0160] According to the UE communication method described above, the UE's transceiver (1310), control unit (1330), and memory (1320) may operate. However, the components of the UE are not limited to the examples described above. For example, the UE may include more or fewer components than the components described above. In addition, the transceiver (1310), control unit (1330), and memory (1320) may be implemented in the form of a single chip. Furthermore, the control unit (1330) may include one or more processors.

[0161] The transceiver (1310) is a general term for the UE's receiver and transmitter, and can transmit and receive signals with other devices. To this end, the transceiver (1310) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver (1310), and the components of the transceiver (1310) are not limited to the RF transmitter and RF receiver.

[0162] In addition, the transmitter / receiver unit (1310) can receive a signal through a wireless channel and output it to the control unit (1330), and transmit the signal output from the control unit (1330) through the wireless channel.

[0163] The memory (1320) can store programs and data required for the operation of the UE. Furthermore, the memory (1320) can store control information or data included in signals acquired from the UE. The memory (1320) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. Furthermore, the memory (1320) may not exist separately but may be included in the control unit (1330).

[0164] The control unit (1330) can control a series of processes so that the UE can operate according to the embodiment of the present disclosure described above.

[0165] FIG. 14 illustrates the structure of a base station according to one embodiment of the present disclosure.

[0166] The base station (or RAN) described with reference to FIGS. 1 to 12B may correspond to the base station (or RAN) of FIG. 14. Referring to FIG. 14, the base station may be composed of a transceiver unit (1410), a memory (1420), and a control unit (1430). According to one embodiment, the base station may include a CU located on the ground as illustrated in FIGS. 1 to 12B.

[0167] According to the communication method of the base station described above, the transceiver (1410), control unit (1430), and memory (1420) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver (1410), control unit (1430), and memory (1420) may be implemented in the form of a single chip. In addition, the control unit (1430) may include one or more processors.

[0168] The transceiver (1410) is a general term for the base station's receiving unit and the base station's transmitting unit, and can transmit and receive signals with other devices. To this end, the transceiver (1410) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver (1410), and the components of the transceiver (1410) are not limited to the RF transmitter and RF receiver.

[0169] In addition, the transmitter / receiver unit (1410) can receive a signal through a wireless channel and output it to the control unit (1430), and transmit the signal output from the control unit (1430) through the wireless channel.

[0170] The memory (1420) can store programs and data required for the operation of the base station. In addition, the memory (1420) can store control information or data included in signals acquired from the base station. The memory (1420) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the memory (1420) may not exist separately but may be configured as part of the control unit (1430).

[0171] The control unit (1430) can control a series of processes so that the base station can operate according to the embodiment of the present disclosure described above.

[0172] FIG. 15 illustrates the structure of a satellite according to one embodiment of the present disclosure.

[0173] The satellites described with reference to FIGS. 1 to 12B may correspond to the satellites of FIG. 15. Referring to FIG. 15, the satellite may be composed of a transceiver unit (1510), a memory (1520), and a control unit (1530). According to one embodiment, the satellite may include the DUs illustrated in FIGS. 1 to 12B.

[0174] According to the communication method of the satellite described above, the satellite's transceiver unit (1510), control unit (1530), and memory (1520) may operate. However, the components of the satellite are not limited to the examples described above. For example, the satellite may include more or fewer components than the components described above. In addition, the transceiver unit (1510), control unit (1530), and memory (1520) may be implemented in the form of a single chip. Furthermore, the control unit (1530) may include one or more processors.

[0175] The transceiver (1510) is a general term for the satellite's receiver and transmitter, and can transmit and receive signals with other devices. To this end, the transceiver (1510) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver (1510), and the components of the transceiver (1510) are not limited to the RF transmitter and RF receiver.

[0176] In addition, the transmitter / receiver unit (1510) can receive a signal through a wireless channel and output it to the control unit (1530), and transmit the signal output from the control unit (1530) through the wireless channel.

[0177] The memory (1520) can store programs and data required for the operation of the satellite. In addition, the memory (1520) can store control information or data included in signals acquired from the satellite. The memory (1520) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the memory (1520) may not exist separately but may be configured as part of the control unit (1530).

[0178] The control unit (1530) can control a series of processes so that the satellite can operate according to the embodiment of the present disclosure described above.

[0179] According to one embodiment of the present disclosure, a method for operating a network device in a non-terrestrial network may include: receiving a first system information block (SIB) transmitted from a central unit (CU) located in a terrestrial network and including configuration information for the non-terrestrial network; generating a second SIB by adding an information element for a satellite located in the non-terrestrial network to the first SIB; and broadcasting the second SIB.

[0180] According to one embodiment, the network device may be implemented in at least one of a packet data convergence control (PDCP) layer, a radio link control (RLC) layer, a medium access control (MAC) layer, and a service data adaptation protocol (SDAP) layer within the DU (820).

[0181] In one embodiment, the network device may be implemented within an on-board computer (OBC) within the satellite located in the non-terrestrial network.

[0182] In one embodiment, the network device may be implemented within a gateway located in the terrestrial network.

[0183] According to one embodiment, the network device may include a SIB classifier that identifies the first SIB; a decoder that converts the format of the first SIB into a bit format; a SIB modifier that adds an information element about the satellite located in the non-terrestrial network to the first SIB to generate a second SIB; and an encoder that converts the format of the second SIB into a format transmitted by the CU.

[0184] According to one embodiment, the method of operating the network device may further include receiving a message requesting additional information about the satellite from a user equipment (UE); and transmitting a third SIB including additional information about the satellite to the UE.

[0185] In one embodiment, the additional information about the satellite may include at least one of a satellite power situation, a satellite antenna directionality error average, a satellite attitude error, and a satellite processor utilization rate.

[0186] In one embodiment, the CU located in the terrestrial network may be located within a base station and may have a radio resource control (RRC) layer.

[0187] The methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0188] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present invention.

[0189] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0190] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present invention via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present invention.

[0191] In the specific embodiments of the present invention described above, components included in the invention are expressed in the singular or plural form depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present invention is not limited to singular or plural components. Even components expressed in the plural form may be composed of singular elements, or even components expressed in the singular form may be composed of plural elements.

[0192] While the detailed description of the present invention has described specific embodiments, it is clear that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims but also by equivalents thereof.

Claims

1. In a method of operating a network device in a non-terrestrial network, An operation of receiving a first SIB (system information block) transmitted from a central unit (CU) located in a terrestrial network and including configuration information for the non-terrestrial network; An operation of generating a second SIB by adding an information element about a satellite located in the above non-terrestrial network to the first SIB; and A method characterized by comprising an action of broadcasting the second SIB.

2. In paragraph 1, A method characterized in that the above network device is implemented in at least one of a PDCP (packet data convergence control) layer, an RLC (radio link control) layer, a MAC (Medium Access Control) layer, and an SDAP (Service Data Adaptation Protocol) layer within a DU.

3. In paragraph 1, A method characterized in that the above network device is implemented in an on-board computer (OBC) within the satellite located in the non-terrestrial network.

4. In paragraph 1, A method characterized in that the above network device is implemented within a gateway located in the above terrestrial network.

5. In paragraph 1, the network device, A SIB classifier that verifies the above first SIB; A decoder that converts the format of the above first SIB into bit form; A SIB modifier (NTN SIB modifier) ​​that creates a second SIB by adding an information element about the satellite located in the non-terrestrial network to the first SIB; and A method characterized by including an encoder that converts the format of the second SIB into a format transmitted by the CU.

6. In paragraph 1, An action of receiving a message from a UE (user equipment) requesting additional information about the satellite; and A method further comprising the action of transmitting a third SIB containing additional information about the satellite to the UE.

7. In paragraph 6, the additional information about the satellite is: A method characterized by including at least one of satellite power status, satellite antenna directionality error mean, satellite attitude error, and satellite processor utilization.

8. In paragraph 1, A method characterized in that the CU located in the above terrestrial network is located within a base station and has an RRC (radio resource control) layer.

9. In a network device in a non-terrestrial network, Transmitter and receiver; and comprising a control unit, said control unit comprising: Receives a first SIB (system information block) that is transmitted from a CU (central unit) located in a terrestrial network and includes configuration information for the non-terrestrial network, A second SIB is created by adding an information element about a satellite located in the above non-terrestrial network to the first SIB, A device characterized by controlling broadcasting of the second SIB.

10. In paragraph 9, The above network device is characterized in that at least one of a PDCP (packet data convergence control) layer, an RLC (radio link control) layer, a MAC (Medium Access Control) layer, and an SDAP (Service Data Adaptation Protocol) layer is implemented in the DU (820).

11. In paragraph 9, A device characterized in that the above network device is implemented within an OBC (on-board computer) within the satellite located in the above non-terrestrial network.

12. In paragraph 9, A device characterized in that the above network device is implemented within a gateway located in the above terrestrial network.

13. In paragraph 9, the network device, A SIB classifier that verifies the above first SIB; A decoder that converts the format of the above first SIB into bit form; A SIB modifier (NTN SIB modifier) ​​that creates a second SIB by adding an information element about the satellite located in the non-terrestrial network to the first SIB; and A device characterized by including an encoder that converts the format of the second SIB into a format transmitted from the CU.

14. In paragraph 9, the control unit, Receive a message from a UE (user equipment) requesting additional information about the satellite; A device characterized by controlling to transmit a third SIB containing additional information about the satellite to the UE.

15. In paragraph 14, the additional information about the satellite is: A device characterized by including at least one of a satellite power situation, a satellite antenna directionality error mean, a satellite attitude error, and a satellite processor utilization.

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