APPARATUS AND METHOD FOR POWER SAVING IN NON-TERRESTRIAL NETWORK

In embodiments, an apparatus of a satellite for providing a non-terrestrial network (NTN) access is provided. The apparatus includes memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, cause the apparatus to transmit, to a terminal through the at least one transceiver, a message including information indicating whether transform precoding of downlink transmission is activated, generate downlink signals based on the information, and transmit, to the terminal through the at least one transceiver, the downlink signals. In a case that the information indicates that the transform precoding is activated, the downlink signals are generated through discrete a fourier transform-spreading (DFT-S) orthogonal frequency division multiplexing (OFDM) scheme, and in a case that the information does not indicate that the transform precoding is activated, the downlink signals are generated through a cyclic prefix (CP)-OFDM scheme.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2023-0176046, filed on Dec. 6, 2023, in the Korean Intellectual Property Office and Korean Patent Application No. 10-2024-0166762, filed on Nov. 20, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Technical Field

The present disclosure generally relates to a non-terrestrial network (NTN) that provides a wireless communication service through a satellite located in an orbit of the earth or an aerial platform flying at high altitude, instead of a base station on the ground, and more particularly, relates to an apparatus and a method for power saving in the non-terrestrial network.

Description of Related Art

In order to complement a terrestrial network that provides a wireless communication system, a non-terrestrial network (NTN) has been introduced. The non-terrestrial network may provide a communication service even in an area where the terrestrial network is difficult to build or in a disaster situation. In addition, due to a recent decrease in a satellite launch cost, an access network environment may be provided efficiently.

SUMMARY

In embodiments, an apparatus of a satellite for providing a non-terrestrial network (NTN) access is provided. The apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the apparatus to transmit, to a terminal through the at least one transceiver, a message including information indicating whether transform precoding of downlink transmission is activated, generate downlink signals based on the information, and transmit, to the terminal through the at least one transceiver, the downlink signals. In a case that the information indicates that the transform precoding is activated, the downlink signals may be generated through a discrete fourier transform-spreading (DFT-S) orthogonal frequency division multiplexing (OFDM) scheme, and in a case that the information does not indicate that the transform precoding is activated, the downlink signals may be generated through a cyclic prefix (CP)-OFDM scheme.

In embodiments, a terminal for communicating with a satellite in a non-terrestrial network (NTN) access is provided. The terminal may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the terminal to receive, from the satellite through the at least one transceiver, a message including information indicating whether transform precoding of downlink transmission is activated and receive, from the satellite through the at least one transceiver, downlink signals based on the information. In a case that the information indicates that the transform precoding is activated, the downlink signals may be received through a discrete fourier transform-spreading (DFT-S) orthogonal frequency division multiplexing (OFDM) scheme. In a case that the information does not indicate that the transform precoding is activated, the downlink signals may be received through a cyclic prefix (CP)-OFDM scheme.

In embodiments, a network apparatus for performing a communication with a satellite for providing a non-terrestrial network (NTN) access is provided. The network apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the network apparatus to identify a plurality of satellites corresponding to a sector related to a specific area, identify a first satellite to be deactivated among the plurality of satellites, based on prediction information related to a specific time, and transmit, to the first satellite through the at least one transceiver, a message for indicating deactivation of the first satellite.

In embodiments, an apparatus of a satellite for providing a non-terrestrial network (NTN) access is provided. The apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the satellite to receive, from a network apparatus through the at least one transceiver, a message for indicating deactivation of the satellite, and in response to the message, deactivate at least one of components of the satellite. The deactivation of the satellite may be associated with a specific area and a specific time.

DETAILED DESCRIPTION

Terms used in the present disclosure are used only to describe a specific embodiment, and may not be intended to limit scope of another embodiment. A singular expression may include a plural expression unless the context clearly means otherwise. Terms used herein, including a technical or a scientific term, may have the same meaning as those generally understood by a person with ordinary skill in the art described in the present disclosure. Among the terms used in the present disclosure, terms defined in a general dictionary may be interpreted as identical or similar meaning to the contextual meaning of the relevant technology and are not interpreted as ideal or excessively formal meaning unless explicitly defined in the present disclosure. In some cases, even terms defined in the present disclosure may not be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach will be described as an example. However, since the various embodiments of the present disclosure include technology that uses both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

Terms referring to a signal (e.g., a signal, information, a message, or signaling), terms referring to a resource (e.g., a symbol, a slot, a subframe, a radio frame, a subcarrier, a resource element (RE), a resource block (RB), a bandwidth part (BWP), or an occasion), terms referring for a calculation state (e.g., a step, an operation, or a procedure), terms referring to data (e.g., a packet, a user stream, information, a bit, a symbol, or a codeword), terms referring to a channel, terms referring to a network entity, terms referring to a device component, and the like, used in the following description are exemplified for convenience of explanation. Therefore, the present disclosure is not limited to terms to be described below, and another term having an equivalent technical meaning may be used.

In the following description, a physical channel and a signal may be used interchangeably with data or a control signal. For example, a physical downlink shared channel (PDSCH) is a term referring to a physical channel through which data is transmitted, but the PDSCH may also be used to refer to data. That is, in the present disclosure, an expression ‘transmitting a physical channel’ may be interpreted equally to an expression ‘transmitting data or a signal through a physical channel’.

Hereinafter, in the present disclosure, upper signaling indicates a signal transmission method transmitted from a base station to a terminal using a downlink data channel of a physical layer or from a terminal to the base station using an uplink data channel of a physical layer. The upper signaling may be understood as radio resource control (RRC) signaling or a MAC control element (hereinafter, ‘CE”).

In addition, in the present disclosure, the term ‘greater than’ or ‘less than’ may be used to determine whether a particular condition is satisfied or fulfilled, but this is only a description to express an example and does not exclude description of ‘greater than or equal to’ or ‘less than or equal to’. A condition described as ‘greater than or equal to’ may be replaced with ‘greater than’, a condition described as ‘less than or equal to’ may be replaced with ‘less than’, and a condition described as ‘greater than or equal to and less than’ may be replaced with ‘greater than and less than or equal to’. In addition, hereinafter, ‘A’ to ‘B’ means at least one of elements from A (including A) to B (including B). Hereinafter, ‘C’ and/or ‘D’ means that at least one of ‘C’ or ‘D’, that is, {′C′, ‘D’, ‘C’ and ‘D’}.

In the present disclosure, a signal quality may be, for example, at least one of reference signal received power (RSRP), beam reference signal received power (BRSRP), a reference signal received quality (RSRQ), a received signal strength indicator (RSSI), a signal to interference and a noise ratio (SINR), a carrier to interference and noise ratio (CINR), a signal to noise ratio (SNR), error vector magnitude (EVM), a bit error rate (BER), and a block error rate (BLER). In addition to the above-described example, of course, other terms having an equivalent technical meaning or other metrics indicating a channel quality may be used. Hereinafter, in the present disclosure, high signal quality means a case in which a signal quality value related to a signal size is large or a signal quality value related to an error rate is small. When the signal quality is high, it may mean that a smooth wireless communication environment is guaranteed. In addition, an optimal beam may mean a beam having the highest signal quality among beams.

The present disclosure describes various embodiments using terms used in a portion of communication standards (e.g., 3rd Generation Partnership Project (3GPP) and European Telecommunications Standards Institute (ETSI)), but this is only an example for explanation. Various embodiments of the present disclosure may be easily modified and applied in another communication system.

FIG. 1 illustrates a wireless communication system.

Referring to FIG. 1, FIG. 1 illustrates a terminal 110 and a base station 120 as a portion of nodes that utilize a wireless channel in a wireless communication system using New Radio (NR) as a wireless interface of Radio Access Technology (RAT). FIG. 1 illustrates only one base station, but the wireless communication system may further include another base station identical or similar to the base station (e.g., NR gNB) 120.

The terminal 110, which is an apparatus used by a user, communicates with the base station 120 through a wireless channel. A link from the base station 120 to the terminal 110 is referred to as a downlink (DL), and a link from the terminal 110 to the base station 120 is referred to as an uplink (UL). In addition, although not illustrated in FIG. 1, the terminal 110 and another terminal may communicate with each other through a wireless channel. At this time, a device-to-device link (D2D) between the terminal 110 and another terminal is referred to as a sidelink, and the sidelink may be used interchangeably with a PC5 interface. In some other embodiments, the terminal 110 may be operated without user involvement. According to an embodiment, the terminal 110, which is an apparatus that performs machine type communication (MTC), may not be carried by a user. In addition, according to an embodiment, the terminal 110 may be a narrowband (NB)-internet of things (IoT) device.

In describing the systems and methods in the present specification, the terminal 110 may be an electronic device used to communicate voice and/or data to the base station 120, and the base station 120 may, in turn, communicate with a network (e.g., a public exchange telephone network (PSTN), the Internet, and the like) of devices.

In addition, the terminal 110 may be referred to as a terminal, ‘user equipment (UE)’, a ‘vehicle’, ‘customer premises equipment (CPE)’, a ‘mobile station’, a ‘subscriber station’, a ‘remote terminal’, a ‘wireless terminal’, an ‘electronic device’, a ‘user device’, an ‘access terminal’, a ‘mobile terminal’, a ‘remote station’, a ‘user terminal’, a ‘subscriber unit’, a ‘mobile device’, or another term having an equivalent technical meaning thereto.

Additionally, examples of terminals 110 include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, and the like. In 3GPP standards, the terminal 110 is typically referred to as UE. However, since scope disclosed in the present specification should not be limited to the 3GPP standards, terms “UE” and “terminal” may be used interchangeably in the present specification to mean a more general term “wireless communication device”. The UE may also more generally be referred to as a terminal device.

The base station 120 is a network infrastructure that provides wireless access to the terminal 110. The base station 120 has coverage defined based on a distance at which a signal may be transmitted. In the 3GPP standards, the base station 120 may generally be referred to as a ‘node B’, an ‘evolved node B (eBodeB, eNB)’, a ‘5th generation node’, a ‘next generation nodeB (gNB)’, a ‘home enhanced or evolved node B (HeNB)’, an ‘access point (AP)’, a ‘wireless point’, a ‘transmission/reception point (TRP)’, or another term having an equivalent technical meaning thereto.

Since scope disclosed in the present specification should not be limited to the 3GPP standards, terms “base station”, “node B”, “eNB”, and “HeNB” may be used interchangeably in the present specification to mean a more general term “base station”. In addition, a term “base station” may be used to indicate an access point. The access point may be an electronic device that provides access to a network (e.g., a local area network (LAN), the Internet, and the like) for wireless communication devices. A term “communication device” may be used to indicate both a wireless communication device and/or a base station. The eNB or the gNB may also more generally be referred to as a base station device.

The base station 120 may communicate with an NR Core Network (NR CN) entity 130. For example, a core network entity 130 may include an access and mobility management function (AMF) that is in charge of a control plane such as terminal 110 access, a mobility control function, and the like, and a User Plane Function (UPF) that is in charge of a control function for user data.

The terminal 110 may perform beamforming with the base station 120. The terminal 110 and the base station 120 may transmit and receive a wireless signal in a relatively low frequency band (e.g., a frequency range 1 (FR 1) of the NR). In addition, the terminal 110 and the base station 120 may transmit and receive a wireless signal in a relatively high frequency band (e.g., a FR 2 (or, a FR 2-1, a FR 2-2, a FR 2-3), or a FR 3 of the NR), a millimeter wave (mm Wave) band (e.g., 28 GHz, 30 GHz, 38 GHz, or 60 GHz)). In order to improve a channel gain, the terminal 110 and the base station 120 may perform the beamforming. Herein, the beamforming may include transmission beamforming and reception beamforming. The terminal 110 and the base station 120 may assign directivity to a transmission signal or a reception signal. To this end, the terminal 110 and the base station 120 may select serving beams through a beam search or a beam management procedure. After the serving beams are selected, subsequent communication may be performed through a resource that is in a Quasi Co-Location (QCL) relationship with a resource transmitting the serving beams.

If large-scale characteristics of a channel transferring a symbol on a first antenna port may be inferred from a channel transferring a symbol on a second antenna port, the first antenna port and the second antenna port may be evaluated to be in the QCL relationship. For example, the large-scale characteristics may include at least one of a delay spread, a doppler spread, a doppler shift, an average gain, an average delay, and a spatial receiver parameter.

Both the terminal 110 and the base station 120 may perform the beamforming, but embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal 110 may or may not perform beamforming. In addition, the base station 120 may or may not perform the beamforming. That is, only one of the terminal 110 and the base station 120 may perform the beamforming, or both the terminal 110 and the base station 120 may not perform the beamforming.

In the present disclosure, a beam, which means a spatial flow of a signal in a wireless channel, may be formed by one or more antennas (or antenna elements), and this formation process may be referred to as the beamforming. The beamforming may include at least one of analog beamforming or digital beamforming (e.g., Precoding). A reference signal transmitted based on the beamforming may include, for example, a demodulation-reference signal (DM-RS), a channel state information-reference signal (CSI-RS), a synchronization signal/physical broadcast channel (SS/PBCH), and a sounding reference signal (SRS). In addition, as a configuration for each reference signal, an information element (IE) such as a CSI-RS resource or an SRS-resource may be used, and this configuration may include information associated with the beam. Information associated with the beam may mean whether a corresponding configuration (e.g., a CSI-RS resource) uses the same spatial domain filter as another configuration (e.g., another CSI-RS resource in the same CSI-RS resource set), or another spatial domain filter, or which reference signal is quasi-co-located (QCL) with, and if it is QCL, which type (e.g., QCL type A, B, C, and D).

Hereinafter, in order to describe embodiments, a terminal may be referred to as UE 110, and a base station may be referred to as a gNB 120.

FIGS. 2A and 2B illustrate an example of a non-terrestrial network (NTN). In FIG. 2A, an example of the non-terrestrial network (NTN) using a transparent satellite is illustrated. In FIG. 2B, an example of the non-terrestrial network (NTN) using a regenerative satellite is illustrated. The NTN means a NG-RAN that provides non-terrestrial NR access to UE (e.g., the UE 110) through an NTN payload and an NTN gateway mounted on an airborne or space-borne NTN vehicle. The NG-RAN may include one or more gNBs (e.g., a gNB 120).

Referring to FIG. 2A, an NTN 200 indicates a network environment according to the transparent satellite. The NTN 200, which is the gNB 120, may include an NTN payload 221 and an NTN gateway 223. The NTN payload 221 is a network node mounted on a phase or a high altitude platform station (HAPS) that provides a connection function between a service link (described later) and a feeder link (described later). The NTN gateway 223 is an earth station disposed on a surface of the earth that provides a connection to the NTN payload 221 using the feeder link. The NTN gateway 223 is a transport network layer (TNL) node. The NTN 200 may provide the non-terrestrial NR access to the UE 110. The NTN 200 may provide the non-terrestrial NR access to the UE 110 through the NTN payload 221 and the NTN gateway 223. A link between the NTN payload 221 and the UE 110 may be referred to as the service link. A link between the NTN gateway 223 and the NTN payload 221 may be referred to as the feeder link. The feeder link may correspond to a wireless link.

The NTN payload 221 may receive wireless protocol data from the UE 110 through the service link. The NTN payload 221 may transparently transmit the wireless protocol data to the NTN gateway 223 through the feeder link. Accordingly, the NTN payload 221 and the NTN gateway 223 may be seen as one gNB 120 from a perspective of the UE 110. The NTN payload 221 and the NTN gateway 223 may communicate with the UE 110 through a Uu interface, which is a general wireless protocol. That is, the NTN payload 221 and the NTN gateway 223 may perform wireless protocol communication with the UE 110 like one gNB 120. The NTN gateway 223 may communicate with a core network entity 235 (AMF or UPF) through an NG interface.

According to an embodiment, the NTN payload 221 and the NTN gateway 223 may use a wireless protocol stack in a control plane of FIG. 3A to be described later. In addition, according to an embodiment, the NTN payload 221 and the NTN gateway 223 may use the wireless protocol stack in a user plane of FIG. 3B.

In FIG. 2A, one NTN payload 221 and one NTN gateway 223 included in the gNB 120 are described, but embodiments of the present disclosure are not limited thereto. For example, a gNB may include a plurality of NTN payloads. In addition, for example, an NTN payload may be provided by a plurality of gNB. That is, an implementation scenario illustrated in FIG. 2A is an example and does not limit embodiments of the present disclosure.

Referring to FIG. 2B, an NTN 250 indicates a network environment according to the regenerative satellite. The NTN 250 may include a satellite 260 operating as the gNB 120. The satellite 260 indicates a space-borne vehicle equipped with a regenerative payload communication transmitter disposed in a low-earth orbit (LEO), a medium-earth orbit (MEO), or a geostationary earth orbit (GEO). The satellite 260 may be referred to as a regenerative payload or a regenerative satellite. The satellite 260 may indicate a payload configured to convert and amplify an uplink RF signal before transmitting the uplink RF signal to a downlink, and the conversion of the signal may mean digital processing capable of including demodulation, decoding, re-encoding, re-modulation and/or filtering. The NTN 250 may include an NTN gateway 265, which is an entity connected to the satellite 260 and disposed on the ground. The NTN gateway 265 is an earth station, disposed on a surface of the earth, that provides a connection to the satellite 260 using the feeder link. The NTN 250 may provide the non-terrestrial NR access to the UE 110. The NTN 250 may provide the non-terrestrial NR access to the UE 110 through the satellite 260 and the NTN gateway 265.

The satellite 260 may be configured to regenerate signals received from the Earth. The Uu interface may be defined between the satellite 260 and the terminal 110. A satellite radio interface (SRI) on the feeder link may be defined between the satellite 260 and the NTN gateway 265. Although not illustrated in FIG. 2B, the satellite 260 may provide inter-satellite links (ISL) between satellites. The ISL may be a transmission link between satellites, and an ISL may be a wireless interface (e.g., an XN interface) defined in 3GPP or an optical interface, not defined in 3GPP. The satellite 260 may communicate with the core network entity 235 (AMF or UPF) through an NG interface, based on the NTN gateway 265. According to an embodiment, the satellite 260 may use the wireless protocol stack in the control plane of FIG. 3A to be described later. In addition, according to an embodiment, the satellite 260 may use the wireless protocol stack in the user plane of FIG. 3B.

In FIG. 2B, the satellite 260 operating as the gNB 120 is described, but embodiments of the present disclosure are not limited thereto. The gNB 120 according to embodiments may be implemented as a distributed deployment using a centralized unit (CU) configured to perform a function of upper layers (e.g., packet data convergence protocol (PDCP), or radio resource control (RRC)) of an access network and a distributed unit (DU) configured to perform a function of lower layers. An interface between the CU and the distributed unit (DU) may be referred to as an F1 interface. The centralized unit (CU) may be in charge of a function of a layer upper than the DU, by being connected to one or more DUs. For example, the CU may be in charge of a function of radio resource control (RRC) and packet data convergence protocol (PDCP) layers, and the DU and a radio unit (RU) may be in charge of a function of a lower layer. The DU may be in charge of a function of radio link control (RLC), media access control (MAC), and physical (PHY) layers. In this distributed deployment, the satellite 260 may be used as the CU or the DU constituting the gNB 120.

FIG. 3A illustrates an example of a control plane (C-plane). Hereinafter, at least a portion of descriptions of a gNB 120 may be understood as pertaining to a satellite 260.

Referring to FIG. 3A, in the C-plane, UE 110 and an AMF 235 may perform non-access stratum (NAS) signaling. In the C-plane, the UE 110 and the gNB 120 may communicate according to a protocol specified in each of a RRC layer, a PDCP layer, a RLC layer, a MAC layer, and a PHY layer.

In an NTN access, a main function of the RRC layer may include at least a portion of the following functions.

In the NTN access, a main function of the PDCP layer may include at least a portion of the following functions.

In the NTN access, a main function of the RLC layer may include at least a portion of the following functions.

In the NTN access, the MAC layer may be connected to multiple RLC layer devices configured in a terminal, and a main function of the MAC may include at least a portion of the following functions.

In the NTN access, the physical layer may perform operations of channel coding and modulating upper layer data, converting into an OFDM symbol and transmitting it to a wireless channel, or demodulating and channel decoding the OFDM symbol received via the wireless channel and transmitting it to the upper layers.

FIG. 3B illustrates an example of a user plane (U-plane). Hereinafter, at least a portion of descriptions of the gNB 120 may be understood as pertaining to the satellite 260.

Referring to FIG. 3B, in a U-plane, UE 110 and a gNB 120 may communicate according to a protocol specified in each of a SDAP layer, a PDCP layer, a RLC layer, a MAC layer, and a PHY layer. For the PDCP layer, the RLC layer, the MAC layer, and the PHY layer, except for the SDAP layer, the description of FIG. 3A may be referenced.

In the NTN access, the SDAP layer may provide a QoS flow of 5GC. A single protocol entity of a SDAP may be configured for each individual PDU session, and a function of the SDAP layer may include at least a portion of the following functions.

FIG. 4 illustrates an example of a resource structure of a time-frequency domain supported by a wireless communication system to which an embodiment proposed in the present specification may be applied. FIG. 4 illustrates a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in downlink or uplink in a 5G NR system to which the present embodiment may be applied.

Referring to FIG. 4, a horizontal axis indicates a time domain, and a vertical axis indicates a frequency domain. A minimum transmission unit in the time domain is an OFDM symbol, and one slot 406 may be configured with Nsymb OFDM symbols 402. Referring to FIG. 4, in the wireless communication system to which the present invention is applied, one radio frame 414 may be defined as having a length of 10 ms, which is configured with 10 subframes having the same length of 1 ms. Additionally, one radio frame 414 may be divided into 5 ms half-frame, and each half-frame includes 5 subframes. In FIG. 4, a slot 406 is configured with 14 OFDM symbols, but a length of a slot may vary according to subcarrier spacing. For example, in case of Numerology having 15-khz subcarrier spacing, the slot is configured with a length of 1 ms, which is the same length as a subframe. In contrast, in case of Numerology having a 30 kHz subcarrier spacing, the slot is configured with 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms.

That is, a subframe and a frame are defined with a fixed time length, and a slot is defined as the number of symbols, so that a time length may vary according to the subcarrier spacing. Referring again to FIG. 4, a radio resource supported by the wireless communication system to which the invention proposed in the present specification may be applied may be configured with a symbol, which is a plurality of time resources, and a sub-carrier, which is a plurality of frequency resource, and each of the time resources and the frequency resources may be represented by a two-dimensional resource grid. In FIG. 4, one quadrilateral, which is the smallest physical resource being configured with one sub-carrier and one symbol in a resource grid, is referred to as a resource element (RE) 412.

In the wireless communication system to which the invention proposed in the present specification may be applied, a minimum transmission unit in the frequency domain is a subcarrier, and a carrier bandwidth constituting the resource grid is configured with New subcarriers 404.

In a time-frequency domain, a basic unit of a resource, which is the resource element (hereinafter referred to as ‘RE’) 412, may be indicated as an OFDM symbol index and a subcarrier index. A resource block 408 may include a plurality of resource elements 412. In the wireless communication system to which the invention proposed in the present specification may be applied, the resource block 408 (or a physical resource block (hereinafter ‘PRB’)) may be defined as Nsymb consecutive OFDM symbols in the time domain and NSCRB consecutive subcarriers in the frequency domain. In a NR system, the resource block (RB) 408 may be defined as NSCRB consecutive subcarriers 410 in the frequency domain. One RB 408 includes NSCRB REs 412 in a frequency axis.

In general, a minimum transmission unit of data is RB and the number of subcarriers is NSCRB=12. The frequency domain may include common resource blocks (CRBs). In a bandwidth part (BWP) on the frequency domain, a physical resource block (PRB) may be defined. The CRB and PRB numbers may be determined according to subcarrier spacing. A data rate may increase in proportion to the number of RBs scheduled to a terminal.

In the NR system, in case of a frequency division duplex (FDD) system that operates a downlink and an uplink separately by frequency, a downlink transmission bandwidth and an uplink transmission bandwidth may be different from each other. A channel bandwidth indicates a radio frequency (RF) bandwidth corresponding to a system transmission bandwidth. Table 1 indicates a portion of a corresponding relationship between the system transmission bandwidth, the subcarrier spacing (SCS), and the channel bandwidth defined in the NR system in a frequency band (e.g., frequency range (FR) 1 (410 MHz to 7125 MHz)) lower than an upper limit (e.g., 7.125) GHz defined in a specification. Additionally, Table 2 indicates a portion of a corresponding relationship between a transmission bandwidth, the subcarrier spacing, and the channel bandwidth defined in the NR system in a frequency band (e.g., a FR2 (24250 MHz to 52600 MHZ)) higher than a lower limit (e.g., 24.25 GHZ) or a FR2-2 (52600 MHZ-71,000 MHz) defined in a specification. For example, the transmission bandwidth of the NR system having a 100 MHZ channel bandwidth at 30 kHz subcarrier spacing is configured with 273 RBs. In Table 1 and Table 2, N/A may be a bandwidth-subcarrier combination that is not supported by the NR system.

Channel bandwidth [MHz]

Channel bandwidth [MHz]

bandwidth

FIG. 5 illustrates an example of a network structure for an NTN. A satellite 260 may be mounted on a space platform or an aerial platform to provide a structure, power, a command, telemetry, posture control (corresponding HAPS) for a satellite, an appropriate thermal environment, and radiation shielding. In FIG. 5, an example in which the satellite 260, as a regenerative payload, operates as a full base station (e.g., a gNB 120) is described.

Referring to FIG. 5, the satellite 260 may operate as the gNB 120. The gNB 120 may communicate with a terminal 110 or may communicate with a core network entity 130. In FIG. 5, a UPF 550 is illustrated as the core network entity 130. An NR Uu interface 502 may be used between the satellite 260 and the terminal 110. According to an embodiment, at least one radio bearer 520 may be generated between the satellite 260 and the terminal 110. For example, the radio bearer 520 may include a data radio bearer (DRB). For example, the radio bearer 520 may include a signaling radio bearer (SRB). An NG interface 504 may be used between the satellite 260 and a core network entity (e.g., AMF and UPF). For example, an N3 interface may be used between the satellite 260 and the UPF. For example, an N2 interface may be used between the satellite 260 and the AMF. According to an embodiment, a traffic tunnel may be generated between the satellite 260 and the core network entity 130. For example, an NG-U tunnel 530 may be generated between the satellite 260 and a UPF 550.

A packet data unit (PDU) session 540 may be generated between UE 110 and the core network entity 130 (e.g., the UPF 550). The PDU session 540 may be used to provide an end-to-end user plane connection between the terminal 110 and a data network through the UPF 550. The PDU session 540 may support one or more quality of service (QOS) flows. For example, the PDU session 540 may support a first QoS flow 511 and a second QoS flow 512. In a user plane, the radio bearer 520 may be mapped to a QoS flow (e.g., the first QoS flow 511 and the second QoS flow 512). According to an embodiment, the satellite 260, which is the gNB 120, may perform mapping between the DRB and the QoS flow.

Although not illustrated in FIG. 5, operation and maintenance (O&M) may be used to provide a wireless access network through the satellite 260. The O&M may provide one or more parameters related to an NTN 500 to the gNB 120 (e.g., the satellite 260). For example, operation and maintenance (O&M) 510 may provide at least following NTN related parameters to the gNB 120 for operation.

FIG. 6A illustrates an example of a control plane of a regenerative satellite (e.g., the satellite 260).

Referring to FIG. 6A, UE 610 may support a protocol of a PHY layer, a MAC layer, a RLC layer, a PDCP layer, and a RRC layer. A satellite 620, which is a gNB, may support the protocol of the PHY layer, the MAC layer, the RLC layer, the PDCP layer, and the RRC layer. For the satellite 620, a description of the satellite 260 may be referenced. A description of the protocol of each layer, the description of FIG. 3A may be referenced. An interface between the UE 610 and the satellite 620 may be a Uu interface.

The satellite 620, which is a gNB mounted on a board or a portion of the gNB, may perform an NG-RAN protocol function. The satellite 620 may perform communication (e.g., IP communication) with an NTN gateway 630 located on the ground through an SRI. The satellite 620 may access 5GC through the NTN gateway 630. As a network entity for the 5GC, an AMF 640 (e.g., AMF 235) and an SMF 650 are exemplified. The satellite 620 may support a protocol of an NG-AP layer, a stream control transmission protocol (SCTP) layer, and an IP layer for communication with the 5GC. The NG-AP layer may be used through an NTN gateway over a SCTP between the AMF 640, which is a 5GC entity, and the satellite 620. NAS signaling between the UE 610 and the AMF 640 may be performed through the satellite 620 and the NTN gateway 630. The NAS signaling may include a NAS-mobility management (MM) interface for the AMF 640. The NAS signaling may include a NAS-SM relay and/or a NAS-session management (SM) for the SMF 650. The NAS signaling may be transmitted through an NG-AP layer protocol between the AMF 640, which is the 5GC entity, and the satellite 620, via the NTN gateway 630.

In FIG. 6A, an example in which a satellite operates as a full gNB is described, but embodiments of the present disclosure are not limited thereto. As a non-limiting example, the satellite may operate as a gNB-DU according to functional separation. Accordingly, the satellite may be configured to support a protocol of the RLC layer, the MAC layer, and the PHY layer.

FIG. 6B illustrates an example of a user plane of a regenerative satellite (e.g., the satellite 260).

Referring to FIG. 6B, the UE 610 may support a protocol of the PHY layer, the MAC layer, the RLC layer, the PDCP layer, and an SDAP layer. The satellite 620, which is the gNB, may support the protocol of the PHY layer, the MAC layer, the RLC layer, the PDCP layer, and the SDAP layer. As a description of the protocol of each layer, the description of FIG. 3B may be referenced. The interface between the UE 610 and the satellite 620 may be the Uu interface.

The satellite 620, which is the gNB mounted on a board, may perform the NG-RAN protocol function. The satellite 620 may perform communication (e.g., IP communication) with the NTN gateway 630 located on the ground through the SRI. The satellite 620 may access the 5GC through the NTN gateway 630. An UPF 680 is exemplified as the network entity for the 5GC. The satellite 620 may support protocols of a General Packet Radio Service (GPRS) tunneling protocol-user plane (GTP-U) layer, a user datagram protocol (UDP) layer, and the IP layer for communication with the 5GC. A PDU session (e.g., the PDU session 540 of FIG. 5) between the UE 610 and the UPF 680 may be generated. A protocol stack of the SRI may be used to transmit a UE user plane between a satellite and an NTN-gateway. Signals on the PDU session may be transmitted through the NTN gateway 630 between the UPF 680, which is the 5GC, and the satellite 620 via a GTP-U tunnel.

In FIG. 6B, an example in which a satellite operates as a full gNB is described, but embodiments of the present disclosure are not limited thereto. As a non-limiting example, the satellite may operate as a gNB-DU according to functional separation. Accordingly, the satellite may be configured to support protocols of the RLC layer, the MAC layer, and the PHY layer.

Signals transmitted from a base station to a terminal may be referred to as downlink signals, and signals transmitted from the terminal to the base station may be referred to as uplink signals. In an LTE standard, a waveform applied to the downlink signals is orthogonal frequency division multiplexing (OFDM), whereas a waveform applied to the uplink signals is discrete fourier transform-spreading (DFT-S) OFDM. In order to solve a problem of a peak-to-average power ratio (PAPR) increasing in the OFDM, the terminal with a limitation in terms of power modulates signals using a DFT-S OFDM scheme when transmitting the uplink signals. In a 5G NR standard, an OFDM scheme (e.g., referred to as cyclic prefix (CP) OFDM) is applied as before for the downlink signals, whereas the OFDM scheme or the DFT-S OFDM scheme is applied adaptively for the uplink signals. That is, in transmitting the uplink signals according to a situation of the terminal, a modulation scheme may be changed.

This assumption is because the base station (network) transmitting the downlink signals has almost no restriction in terms of power consumption, but the terminal transmitting the uplink signals has restriction in terms of power consumption. However, as technology has developed and a non-terrestrial network, that is satellite communication, is introduced to increase coverage while reducing a shadow area, a satellite located in the air transmits the downlink signals instead of an existing network entity disposed on the ground. Since the satellite not only moves in an orbit periodically, but is located on a non-ground other than on the ground, a problem of power may occur. Therefore, in embodiments of the present disclosure, technologies for power saving in the satellite are described.

FIG. 7 illustrates an example of transform precoding. An application of the transform precoding indicates that a waveform modulation scheme is a discrete fourier transform-spreading (DFT-S) scheme.

Referring to FIG. 7, in a non-terrestrial network, a downlink transmission waveform may use transform precoding 701. A satellite (e.g., a satellite 620) may modulate downlink signals through the transform precoding 701, subcarrier mapping 703, Inverse Fast Fourier Transform (IFFT) 705, and CP insertion 707. The transform precoding 701 performs a Spreading process based on Discrete Frequency Transform (DFT). That is, the transform precoding 701 indicates that DFT spreading is performed in an OFDM (hereinafter, CP-OFDM) technique using CP. The downlink transmission waveform may be a CP-OFDM scheme or a DFT-S OFDM scheme according to activation or deactivation of the DFT spreading.

For example, in a case that the transform precoding 701 is activated in downlink data (e.g., PDSCH), the following equation may be referenced.

The MSCPDSCH may indicate a product of the number of RBs scheduled for a PDSCH and the number (NSCRB (=12)) of subcarriers, and symbols may be modulated according to the Equation 1.

FIG. 8 illustrates signaling for downlink transmission using transform precoding. The same reference numbers may indicate an application of the same description.

Referring to FIG. 8, in an operation 801, UE 610 may transmit capability information to a satellite 620. According to an embodiment, the capability information may indicate whether the UE 610 may receive downlink transmission to which the transform precoding is applied. For example, a change in a waveform of downlink signals may cause a hardware change of an entity (e.g., the UE 610) that processes the downlink signals. In a network (e.g., the satellite 620), the satellite 620 may preemptively receive the capability information from the UE 610 to determine whether the downlink transmission is received.

In an operation 803, the satellite 620 may transmit RRC configuration information to the UE 610. The RRC configuration information may include configuration information related to the downlink transmission. For example, the RRC configuration information may include configuration information on a control signal (e.g., a PDCCH). The configuration information on the control signal may indicate whether the transform precoding is activated when the control signal is generated. When the transform precoding is activated, the control signal may be generated according to a DFT-S OFDM scheme. For example, the RRC configuration information may include configuration information on data (e.g., a PDSCH). The configuration information on the data may indicate whether the transform precoding is activated. If the transform precoding is activated, the data may be generated according to the DFT-S OFDM scheme.

According to embodiments, the RRC configuration information may include various information other than simply indicating whether the transform precoding is activated. According to an embodiment, the RRC configuration information may include information on a modulation and coding scheme (MCS) table when the transform precoding is activated. The MCS table may be used to indicate a modulation scheme of data transmitted between the UE 610 and the satellite 620. The UE 610 may check the modulation scheme of an indicated MCS index by using another MCS table according to whether the downlink transmission is the DFT-S OFDM scheme or a CP-OFDM scheme. For example, the RRC configuration information may include the following information.

The IE PDSCH-Config is used to configure the UE specific PDSCH parameters applicable to a

PDSCH-Config information element

The ‘mcs-TableTransformPrecoder’ indicates information on a table to be used by the UE 610 when the transform precoding is activated, and the ‘qam256’ and the ‘qam64LowSe’ indicate tables different to each other. The ‘transformPrecoder’ indicates whether the transform precoding is activated. A difference in an MCS table is because a category of an MCS table that may be supported is different. For example, according to whether the transform precoding is activated in the PDSCH, the modulation scheme for each modulation order may vary as follows.

Transform precoding disabled
Modulation
Modulation

Modulation
Modulation
scheme
order Qm

According to an embodiment, the RRC configuration information may include information on a reference signal. In a 5G NR standard, for channel estimation of downlink signals (e.g., the PDCCH, and the PDSCH), a DMRS or a PTRS may be transmitted together with the downlink signals. Whether the transform precoding is activated may also be indicated for the DMRS and the PTRS. For example, the RRC configuration information may include the following information.

The IE DMRS-DownlinkConfig is used to configure Downlink demodulation reference signals for

DMRS-DownlinkConfig information element

OPTIONAL  -- Need R

DownlinkTransformPrecoding-r16}
 OPTIONAL -- Need M

OPTIONAL  -- Need S

The ‘nPDSCH-Identity’ IE indicate an ID value required when generating a DMRS sequence for the PDSCH. The ‘sequenceGroupHoping’ IE may indicate whether to group hopping when the transform precoding is activated. When group hopping is indicated by another cell-specific parameter, the group hopping may be deactivated for the UE 610 through the IE. The ‘sequenceHopping’ IE may indicate whether to hopping when the transform precoding is activated. When the transform precoding is activated, ‘pi2BPSK-ScrammingID0’ and ‘pi2BPSK-ScrammingID1’ IEs indicate identifier values used to initialization of DM DMRS scrambling.

The IE PTRS-DownlinkConfig is used to configure downlink Phase-Tracking-Reference-Signals

PTRS-DownlinkConfig information element

OPTIONAL  -- Need S

In a case that transform precoding of the downlink transmission is activated, the ‘sampleDensity’ IE and the ‘timeDensityTransformPrecoding’ IE may be used when transmitting the PTRS. The ‘sampleDensity’ IE indicates dependence between a scheduled BW and a PTRS existence. The ‘timeDensityTransformPrecoding’ IE indicates a density on a time axis of an OFDM symbol unit of the PTRS.

In an operation 805, the satellite 620 may perform downlink transmission.

The satellite 620 may generate the downlink signals in the RRC configuration information of the operation 803, as indicated. For example, in a case that the RRC configuration information indicates the DFT-S OFDM scheme (e.g., activation of transform precoding 701), the satellite 620 may generate the downlink signals through a series of procedures illustrated in FIG. 7. For example, in a case that the RRC configuration information indicates the CP-OFDM scheme (e.g., deactivation of transform precoding 701), the satellite 620 may generate the downlink signals through subcarrier mapping 703, Inverse Fast Fourier Transform (IFFT) 705, and CP insertion 707 except the transform precoding 701 among the series of procedures illustrated in FIG. 7. The downlink signals may be transmitted on the PDCCH or the PDSCH, or may include the DMRS and/or the PTRS.

In FIG. 8, through the RRC configuration information, it is indicated whether the downlink transmission of the satellite 620 uses the DFT-S OFDM scheme or uses the CP-OFDM scheme, but embodiments of the present disclosure are not limited thereto. As a non-limiting example, the satellite 620 may indicate the DFT-S OFDM scheme (e.g., activation of the transform precoding 701) through MAC CE or DCI. In addition, in FIG. 8, an example in which the satellite 620 transmits an RRC configuration message to the UE 610 after the UE 610 transmits the capability information to the satellite 620 is described, but embodiments of the present disclosure are not limited thereto. As a non-limiting example, an operation of transmitting the capability information of the operation 801 may be performed independently of a setting operation of the satellite 620. For example, the operation 801 may be omitted.

FIG. 9A illustrates an example of signaling through an NG interface in an NTN. The same reference numbers may indicate an application of the same description. In downlink transmission, whether to use a DFT-S OFDM scheme or a CP-OFDM scheme may depend on a state of a satellite (e.g., a satellite 620). For example, in a case that a power state of the satellite 620 is not normal or a PAPR problem is expected to increase due to a plurality of UEs connected to the satellite 620, the satellite 620 may change a waveform setting for the downlink transmission from the CP-OFDM scheme to the DFT-S OFDM scheme. This determination may be performed by the satellite 620 itself, but may also be performed by a separate network entity (e.g., an AMF 640) that manages the satellite 620.

Referring to FIG. 9A, in an operation 901, the AMF 640 may transmit an indication message for a waveform setting of downlink signals to the satellite 620. The indication message may include information related to the downlink signals on a cell provided by the satellite 620. The satellite 620 may transmit the downlink signals to a terminal (e.g., the UE 610) according to the indication message.

According to an embodiment, the indication message may indicate whether transform precoding (e.g., transform precoding 701) is activated. For example, whether to activate the transform precoding may be determined cell-specifically. The indication message may include a cell identifier (e.g., a physical cell ID or a cell global identity (CGI)). For example, whether to activate the transform precoding may be determined terminal-specifically. The indication message may include a UE ID (e.g., a global unique AMF identifier (GUAMI)) specified in the NG interface. For example, ‘DL-transformPrecodingEnabled’ IE may be included in the indication message.

According to an embodiment, the indication message may indicate a time when the transform precoding (e.g., the transform precoding 701) is activated. When the transform precoding is activated, spectral efficiency is reduced, and complexity of signal processing may increase due to an additional operation of DFT spreading. Therefore, when the activation of the transform precoding is indicated, the indication message may include information (e.g., a timer) on a time when the activation is maintained. The timer may start from a specific time point (e.g., a time point when the downlink transmission is started or a time point when the indication message is received). When the timer expires, the satellite 620 may change the waveform setting from the DFT-S OFDM to the CP-OFDM. For example, ‘DL-transformPrecodingEnabled Timer’ IE may be included in the indication message.

According to an embodiment, the indication message may include information on a geographic area in which the transform precoding is to be used. The satellite 620 may be configured to move along an orbit around a celestial body. Compared to the CP-OFDM scheme, the DFT-S OFDM scheme may provide wide cell coverage and provide high power efficiency. Therefore, in terms of the satellite 620 orbiting the celestial body (e.g., Earth), in an area where a shadow area is expected to be relatively large or in an area where the number of other satellites providing an access network is relatively small, expanding coverage of the satellite 620 may be advantageous for providing a continuous service. For example, the indication message may include information (e.g., a tracking area identity (TAI) list) on a tracking area. For example, ‘TAI list for ‘TransformPrecoding’ IE may be included in the indication message.

The indication message may be newly defined or used as a message defined on an existing NG interface. According to an embodiment, the indication message may be an ‘INITIAL CONTEST SETUP REQUEST’ message. The indication message may include at least one of information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in a UE unit. For example, the indication message may further include an AMF UE NGAP ID, a RAN UE NGAP ID, the GUAMI, a PDU session ID, Single-Network Slice Selection Assistance Information (S-NSSAI), and the like, in addition to the above-described transform precoding-related information.

According to an embodiment, the indication message may be a ‘UE Context Modification Request’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the UE unit. For example, the indication message may further include the AMF UE NGAP ID, the RAN UE NGAP ID, the PDU session ID, the S-NSSAI, and the like, in addition to the above-described transform precoding-related information.

According to an embodiment, the indication message may be a ‘PDU SESSION RESOURCE SETUP REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the UE unit. For example, the indication message may further include the AMF UE NGAP ID, the RAN UE NGAP ID, and the GUAMI, the PDU session ID, the S-NSSAI, and the like, in addition to the above-described transform precoding-related information.

According to an embodiment, the indication message may be a ‘PDU SESSION RESOURCE MODIFY REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the UE unit. For example, the indication message may further include the AMF UE NGAP ID, the RAN UE NGAP ID, and the GUAMI, the PDU session ID, the S-NSSAI, and the like, in addition to the above-described transform precoding-related information.

According to an embodiment, the indication message may be a ‘WRITE-REPLACE WARNING REQUEST’ message. A scenario in which public disaster text is provided through a satellite may be considered. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the UE unit. For example, the indication message may further include a message identifier, a serial number, a repetition period, the number of broadcasts, a warning type, and/or message content.

FIG. 9B illustrates an example of signaling through an F1 interface in an NTN. The same reference numbers may indicate an application of the same description.

Referring to FIG. 9B, in an operation 903, a gNB-CU 920 may transmit an indication message to a gNB-DU 910 corresponding to a satellite. The indication message may include information related to downlink signals on a cell provided by a satellite 620. The satellite 620 may transmit the downlink signals to a terminal (e.g., the UE 610) according to the indication message.

According to an embodiment, the indication message may indicate whether transform precoding (e.g., transform precoding 701) is activated. For example, whether to activate the transform precoding may be determined cell-specifically. The indication message may include a cell identifier (e.g., a physical cell ID or a cell global identity (CGI)). For example, whether to activate the transform precoding may be determined terminal-specifically. The indication message may include a UE ID (e.g., a global unique AMF identifier (GUAMI)) specified in a NG interface. For example, ‘DL-transformPrecodingEnabled’ IE may be included in the indication message.

According to an embodiment, the indication message may indicate a time when the transform precoding (e.g., the transform precoding 701) is activated. When the transform precoding is activated, spectral efficiency is reduced, and complexity of signal processing may increase due to an additional operation of DFT spreading. Therefore, when the activation of the transform precoding is indicated, the indication message may include information (e.g., a timer) on a time when the activation is maintained. The timer may start from a specific time point (e.g., a time point when the downlink transmission is started or a time point when the indication message is received). When the timer expires, the satellite 620 may change the waveform setting from DFT-S OFDM to CP-OFDM. For example, ‘DL-transformPrecodingEnabled Timer’ IE may be included in the indication message.

According to an embodiment, the indication message may include information on a geographic area in which the transform precoding is to be used. The satellite 620 may be configured to move along an orbit around a celestial body. Compared to the CP-OFDM scheme, the DFT-S OFDM scheme may provide wide cell coverage and provide high power efficiency. Therefore, in terms of the satellite 620 orbiting the celestial body (e.g., Earth), in an area where a shadow area is expected to be relatively large or in an area where the number of other satellites providing an access network is relatively small, expanding coverage of the satellite 620 may be advantageous for providing a continuous service. For example, the indication message may include information (e.g., a tracking area identity (TAI) list) on a tracking area. For example, ‘TAI list for ‘TransformPrecoding’ IE may be included in the indication message.

The indication message may be newly defined or used as a message defined on an existing NG interface.

According to an embodiment, the indication message may be a ‘GNB-DU CONFIGURATION UPDATE’ message. The indication message may include at least one of information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in a cell unit. For example, the indication message may include information on serving cells (e.g., serving cell information, and system information of a gNB-DU). The indication message may include information on a serving cell to be added or a serving cell to be modified. The indication message may include DU identification information (e.g., a gNB-DU ID).

According to an embodiment, the indication message may be a ‘NETWORK ACCESS RATE REDUCTION’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. The indication message may further include information (e.g., a public land mobile network (PLMN) identifier, a UAC type, an access category, and an access identifier) for setting parameters for unified access class (uac) barring.

According to an embodiment, the indication message may be a ‘RESOURCE STATUS REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the cell unit. The indication message may include cell information, slice information, and/or beam information (e.g., a SS/PBCH block (SSB) index).

According to an embodiment, the indication message may be a ‘UE CONTEXT SETUP REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the cell unit. The indication message may include a gBNB-CU UE F1AP ID, a gNB-DU UE F1AP ID, a SpCell ID (e.g., a primary cell (PCell) of a master cell group (MCG) and a PCell of a secondary cell group (SCG)), information on a secondary cell (Scell) index, a discontinuous reception (DRX) cycle, signaling radio bearer (SRB) information, and/or data radio bearer (DRB) information, and the like.

According to an embodiment, the indication message may be a ‘UE CONTEXT MODIFICATION REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the cell unit. The indication message may include the gBNB-CU UE F1AP ID, the gNB-DU UE F1AP ID, the SpCell ID (e.g., the primary cell (PCell) of the master cell group (MCG) and the PCell of the secondary cell group (SCG)), the discontinuous reception (DRX) cycle, a secondary cell (Scell) index, and/or information on a RRC container. The RRC container may include a message including the RRC configuration information of FIG. 8 as it is.

According to an embodiment, the indication message may be a ‘DL RRC MESSAGE TRANSFER’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the cell unit. The indication message may include the gBNB-CU UE F1AP ID, the gNB-DU UE F1AP ID, and/or the RRC container. The RRC container may include the message including the RRC configuration information of FIG. 8 as it is.

According to an embodiment, the indication message may be a ‘WRITE-REPLACE WARNING REQUEST’ message. The indication message may include at least one of the information indicating whether the transform precoding (e.g., the transform precoding 701) is activated, the information (e.g., the TAI list) on the geographic area in which the transform precoding is to be used, and the information (e.g., the timer) on the time when the transform precoding is activated. Whether to activate the transform precoding may be indicated in the cell unit. The instruction message may include public warning system (PWS) information (e.g., system information block (SIB) 6, 7, 8), a repetition period, information on the number of broadcasts, and cell information (e.g., CGI).

Examples of changing the waveform setting from the CP-OFDM scheme to the DFT-S OFDM scheme or from the DFT-S OFDM scheme to the CP-OFDM scheme according to a state of the satellite 620 is described through FIG. 7, FIG. 8, FIG. 9A, and FIG. 9B. The downlink transmission using the DFT-S OFDM scheme is advantageous in terms of satellite power efficiency. Meanwhile, by deactivating a satellite determined to be unnecessary or a cell provided by the satellite, power saving of the satellite may be achieved. Hereinafter, through FIG. 10 to FIG. 13, technologies for increasing power efficiency in a non-terrestrial network through deactivation or activation of the satellite or the cell provided by the satellite will be described.

FIG. 10 illustrates an example of a selection procedure of an inactive satellite. The same reference numbers may indicate an application of the same description.

In an operation 1001, an AMF 640 may identify satellites corresponding to a sector. Herein, the sector may indicate a geographic area. A satellite may provide a service for various geographic areas on a celestial body. For example, a geographical area of a region served by a cell in 3GPP may correspond to a tracking area (TA) to manage mobility of UE 610. A tracking area identity (TAI) may be specified by a mobile country code (MCC), a mobile network code (MNC), and a tracking area code (TAC). For example, the geographic area may correspond to the tracking area code (TAC). The AMF 640 may identify satellites related to the geographic area. For another example, the geographic area may be a space area defined according to an orbit of the satellite. The space area may be a unit physically dividing a position of the satellite in a sphere shape surrounding the outside of the celestial body. As the orbit of the satellite is higher from a center of the celestial body, the shape of the sphere surrounding the outside may be larger. As the orbit is higher, the number of the space areas may increase, or extent in a unit space area may increase. The AMF 640 may identify satellites related to the space area. For another example, the geographic area may be an area arbitrarily defined by a business operator managing the satellite. The business operator may manage the geographic area through an area type, a list of serviceable satellites, and/or a set of beams of the serviceable satellites. The geographic area may be specified by a type, a list of satellite(s), and/or a list of beam(s). The AMF 640 may identify satellites included in the list of the satellite(s).

In an operation 1003, the AMF 640 may identify a satellite based on prediction information. The AMF 640 may identify the satellite based on the prediction information among the satellites corresponding to the sector. The satellite indicates a satellite to be deactivated. The prediction information indicates information related to a satellite expected at a specific time point in the future. According to an embodiment, the prediction information may indicate information on an area in which the satellite is expected to be located at a specific time when considering an orbit of the satellite. The time may indicate a season, a month, a day, a year, or a specific time zone of the day. For example, the area may be divided into the tracking area (TA) defined in 3GPP. For example, the area may be divided by a geographic code (e.g., zip code). For example, information on the area may indicate a type of the area. The type of the area may indicate whether it is a continent, an ocean, or an area in which the continent and the sea are mixed. As a non-limiting example, the area may indicate a ratio of the continent to the ocean. According to an embodiment, the prediction information may include information on an attribute for each time. For example, the time may be a season, a month, a day, or a year. For example, the time may indicate a specific time zone (e.g., late night time, working time) of the day. For example, the attribute may include information on a load of a satellite. As a non-limiting example, the load of the satellite may indicate the number of terminals connected to a cell provided by the satellite. The attribute may indicate a load for each cell of the satellite. The satellite may support one or more frequency bands. The attribute may indicate a load for each frequency band (e.g., each cell) in the satellite.

The AMF 640 may identify a satellite. The satellite indicates a satellite selected for deactivation among satellites managed by the AMF 640. The AMF 640 may identify a satellite to be deactivated from among satellites corresponding to the sector of the operation 1001. For example, the satellites corresponding to the sector may include satellites configured to service TAs of a specific TAI list. A specific TA may be associated with a middle of the Pacific Ocean. Satellites capable of providing a service at a specific time in the middle of the Pacific Ocean may be five. In this case, the AMF 640 may determine to deactivate four satellites. Therefore, the AMF 640 may identify the four satellites as satellites to be deactivated. For example, the satellites corresponding to the sector may include satellites associated with a specific space area. The specific space area may be in a middle of a city center. At a specific time (e.g., late night time), satellites that may be serviced through the specific space area may be 120. When considering in terms of a reduced amount of communication of users in the late night time zone, the AMF 640 may determine to deactivate partial satellites. As an example, the AMF 640 may identify 60 satellites as satellites to be deactivated. For example, the satellites corresponding to the sector may include satellites configured to service an area separately defined by the business operator. For example, the area may indicate a desert. Since the number of users is relatively small in the desert, the relatively small number of satellites may be required. Satellites available in the desert may be 100. In order to save power of unnecessary satellites in the desert, the AMF 640 may determine to deactivate partial satellites. As an example, the AMF 640 may identify 90 satellites as satellites to be deactivated.

In an operation 1005, the AMF 640 may transmit a control signal to a satellite 620. The control signal may indicate deactivation of the satellite 620. The control signal may include a deactivation command. The control signal may provide various information as well as activation/deactivation.

According to an embodiment, the control signal may indicate a deactivation range of a satellite. The satellite may not be deactivated unconditionally according to the control signal, but the satellite may be deactivated according to the deactivation range. For example, the deactivation range may be defined in a cell unit. The control signal may include a cell identifier to be deactivated together with the deactivation command. For example, the deactivation range may be defined in a DRB unit. The control signal may include a DRB identifier to be deactivated together with the deactivation command. For example, the deactivation range may be defined in an SRB unit. The control signal may include an SRB identifier to be deactivated together with the deactivation command. For example, the deactivation range may be defined in a DU unit. The control signal may include a DU ID to be deactivated together with the deactivation command.

According to an embodiment, the control signal may indicate a deactivation time of a satellite. For example, the control signal may include information on a timer. The information on the timer may indicate a time period (e.g., a length of the timer) in which the satellite is deactivated. The timer may start from a time point when the control signal is transmitted. When the timer expires, the satellite may be activated again.

According to an embodiment, the control signal may indicate an inactive area of a satellite. The satellite may not be deactivated unconditionally according to the control signal, but the satellite may be deactivated in a case of entering the deactivation area. For example, the inactive area may be indicated by a TAI list. The control signal may include the TAI list. For example, the inactive area may be indicated by the TAI. The control signal may include the TAI. For example, the inactive area may be indicated by the TAC. The control signal may include the TAC. For example, the inactive area may be indicated by an identifier of a space area. The control signal may include the identifier. For example, the inactive area may be an area defined by a business operator, and the control signal may include a type of the area, an identifier for the area, and/or a list of satellites provided through the area.

According to one embodiment, the control signal may indicate a frequency band that is a target for deactivation of a satellite. For example, the frequency band may indicate a frequency band supporting satellite communication. The control signal may indicate a specific band to be deactivated among frequency bands supporting satellite communication. For example, the frequency band may be related to a cell. The control signal may indicate a cell to be deactivated among cells corresponding to specific frequency bands.

According to an embodiment, the control signal may include information on a type of an area in which a satellite is to be deactivated. The satellite may not unconditionally deactivated according to the control signal, but the satellite may be deactivated, in a case of entering an area of a specific type. For example, the type may indicate whether it is a continent or an ocean, a city center or an outskirts, or a ratio of a terrestrial network to a non-terrestrial network.

According to an embodiment, the control signal may include information on a cause of deactivation of a satellite. The control signal may include information on a cause of why the satellite is deactivated. For example, the cause may be indicated by one of the following values.

Although the deactivation of the satellite is described as an example in FIG. 10, embodiments of the present disclosure are not limited thereto. The sector and the prediction information described with reference to FIG. 10 may be used for activation of the satellite. The AMF 640 may identify satellites corresponding to the sector and identify satellites to be activated from among the satellites. The AMF 640 may transmit the control signal for indicating activation to the satellite.

Operations between the AMF 640 and the satellite 620 is described in FIG. 10, but embodiments of the present disclosure are not limited thereto. An entity for managing a satellite may be used instead of the AMF 640. For example, in a case that a plurality of DUs are connected to a CU, and each DU corresponds to a satellite, the CU may identify the satellite (or the satellite to be activated) to be deactivated and transmit the control signal to the DU corresponding to the identified satellite. The control signal may be defined on an F1 interface. An example of a detailed message may be defined through FIG. 11B. For example, satellites may form a group. The group may include a master satellite and one or more slave satellites. The master satellite in the group may identify a slave satellite (or a slave satellite to be activated) to be deactivated and transmit the control signal to the identified slave satellite. The control signal may be defined on an XN interface. An example of the detailed message may be defined through FIG. 12.

Deactivation indication information (e.g., ‘deactivation indication’ IE) of the control signal of the operation 1005 may be displayed, for example, in the following format.

IE type and

IE/Group Name
reference
Semantics description

Deactivation
{Deactivation,
Indication of deactivation of satellite

Cell list

Indication of cells to be deactivated

DRB ID

Indication of DRBs to be deactivated

SRB ID

Indication of SRBs to be deactivated

Timer

Deactivation Timer

gNB DU ID

DU to be deactivated

Service Area

Service Area to be deactivated(e.g.,

Frequency Band

Frequency band to be deactivated

Area Type

Cause

Cause of Deactivation of satellite

Activation indication information (e.g., ‘activation indication’ IE) of the control signal of the operation 1005 may be displayed, for example, in the following format.

IE type and

IE/Group Name
reference
Semantics description

Activation
{Activation,
Indication of activation of satellite

Cell list

Indication of cells to be activated

DRB ID

Indication of DRBs to be activated

SRB ID

Indication of SRBs to be activated

Timer

Activation Timer

gNB DU ID

DU to be activated

Service Area

Service Area to be activated(e.g.,

Frequency Band

Frequency band to be activated

Area Type

Cause

Cause of activation of satellite

FIG. 11A illustrates an example of signaling through an NG interface for indicating an inactive satellite. The same reference numbers may indicate an application of the same description.

Referring to FIG. 11A, in an operation 1101, an AMF 640 may transmit a request message to a satellite 620. The request message may include a deactivation command (or an activation command). The request message may indicate a deactivation range (e.g., a cell identifier, a DRB identifier, an SRB identifier, and/or a DU ID) of a satellite. The request message may include information (or information on an activation time) on a deactivation time. The request message may include information (or information on an active area) on an inactive area. In a case of entering the inactive area, a satellite receiving the control signal may be deactivated. The request message may indicate a frequency band (or a frequency band to be activated) to be deactivated of a satellite. The request message may include information on a type of an area (or an area to be activated) in which a satellite is to be deactivated. The request message may include information on the type of the area in which the satellite is to be deactivated.

In an operation 1103, the satellite 620 may transmit a response message to the AMF 640.

The request message and the response message may be messages separately defined for deactivation of a satellite or may be used together with messages defined in a TS 38.413 standard.

According to an embodiment, the request message may be a ‘PDU SESSION RESOURCE SETUP REQUEST’ message, and the response message may be a ‘PDU SESSION RESOURCE SETUP RESPONSE’ message.

IE type and
Semantics

Assigned

Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

AMF UE
M

YES
reject

RAN UE
M

YES
reject

RAN
O

YES
ignore

Paging

Priority

YES
reject

YES
reject

Session

Resource

Setup

Request

Session

Resource

Setup

Request

Session

Session

Session

STRING
the PDU

Resource

Session

Setup

Resource

Request

Setup

Transfer

Request

Transfer IE

specified in

YES
ignore

Aggregate

Maximum

Bit Rate

Deactivation
O

Indication of

command

deactivation of

satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service
O

Service Area to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

Deactivation of

satellite

For IEs according to the Table 9, the Table 7 for deactivation indication and a 3GPP TS 38.413 standard may be referenced.

According to an embodiment, the request message may be a PDU SESSION RESOURCE MODIFY REQUEST message, and the response message may be a PDU SESSION RESOURCE MODIFY RESPONSE′ message.

IE type and
Semantics

Assigned

Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

AMF UE
M

YES
reject

RAN UE
M

YES
reject

RAN
O

YES
ignore

Paging

Priority

YES
reject

Session

Resource

Modify

Request

Session

Resource

Modify

Request

Session

Session

STRING
the PDU

Resource

Session

Modify

Resource

Request

Modify

Transfer

Request

Transfer IE

specified in

YES
reject

Deactivation
O

Indication of

command

deactivation of

satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service
O

Service Area to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

Deactivation of

satellite

For IEs according to the Table 10, the Table 7 for the 3GPP TS 38.413 standard and the deactivation indication may be referenced.

According to an embodiment, the request message may be an ‘AMF CONFIGURATION UPDATE’ message, and the response message may be an ‘AMF 5 CONFIGURATION UPDATE ACKNOWLEDGE’ message.

IE type and
Semantics

Assigned

Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

AMF
O

YES
reject

Served

YES
reject

AMF Name

ENUMERATED

YES
ignore

Relative
O

YES
ignore

Capacity

YES
reject

Support

Support

Identity

Support

per PLMN or

9.3.3.44
If the NID IE
YES
reject

Support

is included, it

identifies a

together with

the PLMN

9.3.1.191
Additional
YES
reject

Slice

Supported

Support

per PLMN

YES
ignore

Association

to Add

Association

to Add

CP Transport
AMF
—

Layer
Transport

Association

Information
Layer

Address

9.3.2.6
information

used to set

up the new

Association

Usage

Address

Weight

Factor

YES
ignore

Association

to Remove

Association

to Remove

CP Transport
Transport
—

Layer
Layer

Association

Information
Address of

Address

CP Transport
Transport
YES
reject

Association

Layer
Layer

Transport

Address
Address of

Layer

Address

YES
ignore

Association

to Update

Association

to Update

CP Transport
AMF
—

Layer
Transport

Association

Information
Layer

Address

9.3.2.6
information

used to

identify the

association

to be

TNL
O

Association

Usage

Address

Weight

Factor

Extended
O

YES
ignore

Deactivation
O

Indication of

command

of satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service
O

Service Area

to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

of satellite

For IEs according to the Table 11, the Table 7 for the 3GPP TS 38.413 standard and the deactivation indication may be referenced.

FIG. 11B illustrates an example of signaling through an F1 interface for indicating an inactive satellite. The same reference numbers may indicate an application of the same description.

Referring to FIG. 11B, in an operation 1151, a gNB-CU 1120 may transmit a request message for a waveform setting to a gNB-DU 1100 corresponding to a satellite (e.g., a satellite 620). Herein, the gNB-DU 1100 performs a DU function of the satellite 620. The request message may include a deactivation command (or an activation command). The request message may indicate a deactivation range (e.g., a cell identifier, a DRB identifier, an SRB identifier, and/or a DU ID) of a satellite. The request message may include information (or information on an activation time) on a deactivation time. The request message may include information (or information on an active area) on an inactive area. In a case of entering the inactive area, a satellite receiving the control signal may be deactivated. The request message may indicate a frequency band (or a frequency band to be activated) to be deactivated of a satellite. The request message may include information on a type of an area (or an area to be activated) in which a satellite is to be deactivated. The request message may include information on the type of the area in which the satellite is to be deactivated.

In an operation 1153, the gNB-DU 1110 corresponding to the satellite (e.g., the satellite 620) may transmit a response message to the gNB-CU 1120.

The request message and the response message may be messages separately defined for deactivation of a satellite or may be used together with messages defined in a TS 38.473 standard.

According to an embodiment, the request message may be a GNB-CU configuration update message, and the response message may be a gNB-CU configuration update confirmation message. A gNB-CU 1120 may transmit the gNB-CU configuration update message to a gNB-DU 1110 through the F1 interface. The gNB-DU 1110 may transmit the GNB-CU configuration update confirmation message to the gNB-CU 1120 through the F1 interface. The GNB-CU configuration update message may include at least one of the information in the Table 7 or the Table 8. For example, the request message may include the following IEs as exemplified in Table 12.

IE type and
Semantics

Assigned

Name
Presence
Range
reference
description
Criticality
Criticality

Message Type
M

YES
reject

Transaction ID
M

YES
reject

Cells to be

List of cells
YES
reject

Activated List

to be

activated or

modified

>Cells to

EACH
reject

be Activated

List Item

>> NR CGI
M

>> NR PCI
O

Cell ID

9.3.1.42
RRC
YES
reject

container

System

with system

Information

information

owned by

YES
ignore

PLMN List

9.3.1.76
This is
YES
ignore

Available

included if

PLMN List

Available

PLMN List

IE is

included

and if more

Available

PLMNs is to

be signalled.

configuration

sent by

the IAB-

9.3.1.163
Indicates
YES
ignore

the available

ID List

If this IE is

the content

of the

Available

PLMN List

IE and

Extended

Available

PLMN List

IE if present

in the Cells

to be

Activated

List Item IE

is ignored.

YES
ignore

Broadcast

Neighbour

Cell List

Cells to be

List of cells
YES
reject

to be

>Cells to be

EACH
reject

List Item

>> NR CGI
M

YES
ignore

Association

To Add List

EACH
ignore

Association

To Add

Item IEs

CP Transport Layer
Transport
—

Association

Address
Layer

Transport

9.3.2.4
Address of

Layer

the gNB-

Information

Association

Usage

association

is only used

for UE-

associated

or non-UE-

associated

or both. For

usage of

this IE, refer

to TS

YES
ignore

Association

To Remove

EACH
ignore

Association

To Remove

Item IEs

CP Transport Layer
Transport
—

Association

Address
Layer

Transport

9.3.2.4
Address of

Layer

the gNB-

Address

CP Transport Layer
Transport
YES
reject

Association

Address
Layer

Transport

9.3.2.4
Address of

Layer

the gNB-

Address

YES
ignore

Association

To Update

EACH
ignore

Association

To Update

Item IEs

CP Transport Layer
Transport
—

Association

Address
Layer

Transport

9.3.2.4
Address of

Layer

the gNB-

Address

Association

Usage

association

is only used

for UE-

associated

or non-UE-

associated

or both. For

usage of

this IE, refer

to TS

Cells to be

List of cells
YES
ignore

barred List

to be

>Cells to

EACH
ignore

be barred

List Item

ENUMERATED

Barred

ENUMERATED

Barred

List of
YES
reject

Resources

EACH
reject

Resources

List Item

Sharing

Group ID

cells

involved in

resource

coordination

with the NR

cells

affiliated

with the same

Spectrum

Sharing

List of
—

applicable

Cells List

Cells

List Item

the E-

Cell ID

UTRAN Cell

Identifier IE

contained in

the ECGI as

defined in

9.2.14 in TS

Information

Neighbour

YES
ignore

Information

EACH
ignore

Information

List Item

>>NR CGI
M

Configuration

Transport
O

YES
ignore

Layer Address

Uplink BH
O

YES
reject

Mapping

BAP Address
O

9.3.1.111
Indicates a
YES
ignore

BAP address

assigned to

the IAB-

CCO
O

9.3.1.211
Indicates
YES
Ignore

Assistance

Information

Assistance

Information

for cells and

beams

served by

the gNB-DU

of the same

node or for

cells and

beams not

served by

the gNB-

Cells for SON
O

YES
ignore

gNB-CU Name
O

name of the

Extended
O

YES
ignore

Deactivation
O

Indication of

command

of satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area
O

Service

Area to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service

Area type

Cause
O

Cause of

of satellite

For IEs according to the Table 12, the Table 7 for a 3GPP TS 38.473 standard and deactivation indication may be referenced.

FIG. 12 illustrates an example of signaling through an XN interface for indicating an inactive satellite. The same reference numbers may indicate an application of the same description. As a link between satellites, an inter-satellite link (ISL) may be used. A first base station (e.g., a RAN node, and a gNB) may correspond to a satellite 620, and a second base station (e.g., the RAN node, and the gNB) may correspond to a base station 1220 located on the ground.

Referring to FIG. 12, in an operation 1201, the satellite 620 may transmit a first message to the base station 1220 through the XN interface. The base station 1220 may receive the first message from the satellite 620.

In an operation 1203, the base station 1220 may transmit a second message to the satellite 620 through the XN interface. The satellite 620 may receive the second message from the base station 1220.

According to an embodiment, the first message may be a handover request message, and the second message may be a handover response message. The satellite 620 may transmit the handover request message to the base station 1220 through the XN interface. The base station 1220 may transmit the handover response message to the satellite 620 through the XN interface. The handover request message may include at least one of the information in the Table 7 and the Table 8. The handover response message may include at least one of the information in the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 13.

IE type and
Semantics

Assigned

Name
Presence
Range
reference
description
Criticality
Criticality

Message Type
M

YES
reject

Source NG-
M

NG-RAN node
Allocated at the source NG-
YES
reject

RAN node UE

UE XnAP ID
RAN node

reference

Cause
M

YES
reject

Target Cell
M

9.2.3.25
Includes either an E-UTRA CGI
YES
reject

Global ID

or an NR CGI

YES
reject

UE Context

YES
reject

Information

>NG-C UE
M

AMF UE
Allocated at the AMF on the
—

associated

Signalling

reference

CP Transport
This IE indicates the AMF's IP
—

Layer
address of the SCTP

association

Information
association used at the source

address at

Note: If no UE TNLA binding

exists at the source NG-RAN

node, the source NG-RAN

node indicates the TNL

association address it would

have selected if it would have

had to create a UE TNLA

>UE Security
M

Capabilities

>AS Security
M

Information

>Index to
O

Selection

Priority

Aggregate

Maximum Bit

Resources To

containing UL tunnel

Be Setup List

information per PDU Session

and in addition, the source side

QoS flow ⇔ DRB mapping

>RRC Context
M

OCTET
Either includes the
—

message as defined in

[14], or the

NB message as defined in

[14], if the target NG-RAN node

is an ng-eNB,

or the

message as defined in

[10], if the target NG-RAN node

is a gNB.

9.2.3.47
Includes the necessary
—

Reporting

parameters for location

Information

Restriction

>5GC Mobility
O

YES
ignore

Restriction

List Container

>NR UE
O

9.2.3.107
This IE applies only if the UE is
YES
ignore

authorized for NR V2X

Aggregate

Maximum Bit

>LTE UE
O

9.2.3.108
This IE applies only if the UE is
YES
ignore

authorized for LTE V2X

Aggregate

Maximum Bit

YES
ignore

Based MDT

PLMN List

>UE Radio
C

YES
reject

Capability ID

YES
ignore

Session

Information

>5G ProSe
O

NR UE
This IE applies only if the UE is
YES
ignore

Sidelink
authorized for 5G ProSe

Aggregate

Maximum Bit

Maximum Bit

>UE Slice
O

YES
ignore

Maximum Bit

Rate List

Trace Activation
O

YES
ignore

Masked IMEISV
O

YES
ignore

UE History
M

YES
ignore

Information

UE Context
O

YES
ignore

Reference at

the S-NG-RAN

RAN Node ID

node UE

Conditional
O

YES
reject

Handover

Information

Request

>CHO Trigger
M

ENUMERATED

NG-RAN node
Allocated at the target NG-RAN
—

RAN node UE
ifCHOmod

UE XnAP ID
node

INTEGER

Arrival

Probability

NR V2X
O

YES
ignore

Services

Authorized

YES
ignore

Services

Authorized

PC5 QoS
O

9.2.3.109
This IE applies only if the UE is
YES
ignore

Parameters

authorized for NR V2X

Mobility
O

BIT STRING
Information related to the
YES
ignore

Information

node provides it in order to

enable later analysis of the

conditions that led to a wrong

UE History
O

YES
ignore

Information

from the UE

IAB Node
O

ENUMERATED

YES
reject

Indication

No PDU
O

ENUMERATED
This IE applies only if the UE is
YES
ignore

Session

Indication

Time
O

YES
ignore

Assistance

Information

QMC
O

YES
ignore

Configuration

Information

5G ProSe
O

YES
ignore

Authorized

9.2.3.160
This IE applies only if the UE is
YES
ignore

authorized for 5G ProSe

Parameters

Deactivation
O

Indication of deactivation of

command

satellite

Cell list
O

Indication of cells to be

DRB ID
O

Indication of DRBs to be

SRB ID
O

Indication of SRBs to be

Timer
O

Deactivation Timer

gNB DU ID
O

DU to be deactivated

Service Area
O

Service Area to be

Frequency
O

Frequency band to be

Area Type
O

Service Area type (e.g.,, sea,

Cause
O

Cause of Deactivation of

satellite

For IEs according to the Table 13, the Table 7 for a 3GPP TS 38.423 standard and deactivation indication may be referenced.

According to an embodiment, the first message may be a cell activation request message, and the second message may be a cell activation response message. The satellite 620 may transmit the cell activation request message to the base station 1220 through the XN interface. The base station 1220 may transmit the cell activation response message to the satellite 620 through the XN interface. The cell activation request message may include at least one of the information in the Table 7 and the Table 8. The cell activation response message may include at least one of the information in the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 14.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message Type
M

YES
reject

CHOICE Served
M

YES
reject

Cells To Activate

>>>>NR CGI
M

Cells List

Cells item

UTRA CGI

Activation ID
M

INTEGER
Allocated by the
YES
reject

Interface
O

YES
reject

Instance

Indication

Deactivation
O

Indication of

command

deactivation of

satellite

Cell list
O

Indication of cells

to be deactivated

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area
O

Service Area to be

Frequency Band
O

Frequency band

to be deactivated

Area Type
O

Service Area

Cause
O

Cause of

Deactivation of

satellite

For IEs according to the Table 14, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

According to an embodiment, the first message may be an XN setup request message, and the second message may be an XN setup response message. The satellite 620 may transmit the XN setup request message to the base station 1220 through the XN interface. The base station 1220 may transmit the XN setup response message to the satellite 620 through the XN interface. The XN setup request message may include at least one of the information in the Table 7 and the Table 8. The XN setup response message may include at least one of the information in the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 15.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

Global NG-
M

YES
reject

RAN Node ID

TAI Support
M

9.2.3.20
List of supported
YES
reject

TAs and

associated

AMF Region
M

9.2.3.83
Contains a list of
YES
reject

Information

all the AMF

Regions to

which the NG-

RAN node

List of

Contains a list of
YES
reject

Served Cells

cells served by

the gNB. If a

partial list of

cells is

signalled, it

contains at least

one cell per

carrier

configured at

the gNB

Information

Information

Information

YES
ignore

Cell Specific

Info Request

List of

Contains a list of
YES
reject

Served Cells

cells served by

the ng-eNB. If a

partial list of

cells is

signalled, it

contains at least

one cell per

carrier

configured at

the ng-eNB

Information

Information

Information

9.2.2.75
Associated with
YES
ignore

Offset

the ECGI IE in

the Served Cell

Information E-

UTRA IE

Interface
O

YES
reject

Instance

Indication

TNL
O

YES
ignore

Configuration

Partial List
O

Partial
Value “partial”
YES
ignore

Indicator NR

List
indicates that a

Indicator
partial list of

9.2.2.46
cells is included

in the List of

Served Cells NR

Cell and
O

9.2.2.41
Contains NR
YES
ignore

Capacity

cell related

Assistance

assistance

Information

Partial List
O

Partial
Value “partial”
YES
ignore

List
indicates that a

Indicator
partial list of

9.2.2.46
cells is included

in the List of

Served Cells E-

Cell and
O

Capacity

UTRA cell

Assistance

related

Information

assistance

Local NG-
C

YES
ignore

RAN Node

Identifier

Neighbour

YES
ignore

Node List

Node ID

RAN Node

Identifier

Deactivation
O

Indication of

command

deactivation of

satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area

to be

other ID)

Frequency
O

Frequency band

to be

Area Type
O

Service Area

Cause
O

Cause of

Deactivation of

satellite

For IEs according to the Table 15, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

According to an embodiment, the first message may be an NG-RAN node configuration update message, and the second message may be an NG-RAN node configuration update confirmation message. The satellite 620 may transmit the NG-RAN node configuration update message to the base station 1220 through the XN interface. The base station 1220 may transmit the NG-RAN node configuration update confirmation message to the satellite 620 through the XN interface. The NG-RAN node configuration update message may include at least one of the information in the Table 7 and the Table 8. The NG-RAN node configuration update confirmation 10 message may include at least one of the information in the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 16.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

TAI Support
O

9.2.3.20
List of
GLOBAL
reject

supported

TAs and

associated

CHOICE
M

YES
ignore

Initiating

Node Type

YES
ignore

Cells To

Update NR

YES
ignore

Assistance

Information

>>Cell
C

YES
ignore

Assistance

Information

YES
ignore

Specific

Request

YES
ignore

Cells to

Update

YES
ignore

Assistance

Information

YES
ignore

Assistance

Information

TNLA To

YES
ignore

Add List

>TNLA To

Add Item

CP Transport
CP
—

Transport

Layer
Transport

Layer

Information
Layer

Information

9.2.3.31
Information

of NG-

Association

Usage

TNLA To

YES
ignore

Update List

>TNLA To

Update Item

CP Transport
CP
—

Transport

Layer
Transport

Layer

Information
Layer

Information

9.2.3.31
Information

of NG-

Association

Usage

TNLA To

YES
ignore

Remove

>TNLA To

Remove

CP Transport
CP
—

Transport

Layer
Transport

Layer

Information
Layer

Information

9.2.3.31
Information

of NG-

Global NG-
O

YES
reject

RAN Node

AMF Region
O

AMF Region
List of all
YES
reject

Information

Information
added

To Add

Regions to

which the

AMF Region
O

AMF Region
List of all
YES
reject

Information

Information
deleted

To Delete

Regions to

which the

Interface
O

YES
reject

Instance

Indication

TNL
O

YES
ignore

Configuration

Coverage

List of
GLOBAL
reject

Modification

cells with

modified

Modification

RAN Cell
Cell Global

Identity
Identifier

Identity

9.2.2.27
of the cell

to be

Coverage

State

that the

cell is

Other

values

Indicates

that the

cell is

active and

also indicates

the coverage

configuration

of the

Deployment

change-
the Cell

Status

Indicator

State is

planned to

be used at

the next

Cells

RAN Cell
Cell Global

Identity
Identifier

Identity

9.2.2.27
of a cell

that may

replace all

or part of

the coverage

of the cell

to be modified.

List of
—

Coverage

Modification

beams with

modified

Coverage

Modification

Index

beam to be

Coverage

State

that the

SSB beam

is inactive.

Other values

Indicates

that the

SSB beam

is active

and also

indicates

the coverage

configuration

of the

concerned

ENUMERATED
Indicates
YES
ignore

Modification

(coverage,
the reason

Cause

cell edge
for the

modification

in NG-

Local NG-
O

YES
ignore

RAN Node

Identifier

Neighbour

YES
ignore

Node List

Node ID

Identifier

Local NG-
O

YES
ignore

RAN Node

RAN Node

Identifier

Identifier

Removal

Deactivation
O

Indication of

command

of satellite

Cell list
O

Indication

of cells to

be deactivated

DRB ID
O

Indication

of DRBs to

be deactivated

SRB ID
O

Indication

of SRBs to

be deactivated

Timer
O

Timer

gNB DU ID
O

DU to be

Service
O

Service

Area to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service

Area type

Cause
O

Cause of

of satellite

For IEs according to the Table 16, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

According to an embodiment, the first message may be an S-node addition request message, and the second message may be an S-node addition response message. The satellite 620 may transmit the S-node addition request message to the base station 1220 through the XN interface. The base station 1220 may transmit the S-node addition response message to the satellite 620 through the XN interface. The S-node addition request message may include at least one of 5 the information of the Table 7 and the Table 8. The S-node addition response message may include at least one of the information of the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 17.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

NG-RAN
Allocated at
YES
reject

node UE

node UE
the M-NG-

XnAP ID
RAN node

UE Security
M

YES
reject

Capabilities

YES
reject

node Security

UE Aggregate
The UE
YES
reject

node UE

Maximum Bit
Aggregate

Aggregate

Rate
Maximum Bit

Maximum Bit

9.2.3.17
Rate is split

RAN node UE

Aggregate

Maximum Bit

Rate and S-

UE Aggregate

Maximum Bit

Rate which are

enforced by M-

and S-NG-

RAN node

Selected
O

PLMN Identity
The selected
YES
ignore

9.2.2.4
PLMN of the

SCG in the S-

Mobility
O

YES
ignore

Restriction

Index to
O

YES
reject

Selection

Priority

PDU Session

YES
reject

Resources

To Be Added

Session

neither the

Resources

PDU Session

To Be

Resource

Added Item

Setup Info -

SN terminated

nor the

PDU Session

Resource

Setup Info -

MN terminated

is present in a

PDU Session

Resources To

Be Added Item

conditions as

specified in

Session ID

PDU Session

RAN node

Aggregate

Maximum Bit

Session

Aggregate

Maximum

Bit Rate

Session

Resource

Setup Info -

terminated

Session

Resource

Setup Info -

terminated

OCTET
Includes the
YES
reject

node to S-

message as

defined in

Container

11.2.2 of TS

NG-RAN
Allocated at
YES
reject

node UE

node UE
the S-NG-RAN

XnAP ID
node

Expected UE
O

YES
ignore

Behaviour

Requested
O

ENUMERATED
Indicates that
YES
reject

Split SRBs

(srb1, srb2,
resources for

PCell ID
O

YES
reject

RAN Cell

Identity

Desired
O

YES
ignore

Activity

Notification

Level

DRB List
Indicates the
YES
reject

9.2.1.29
list of DRB IDs

that the S-NG-

RAN node

may use for

Bit Rate
The S-NG-
YES
reject

9.2.3.4
RAN node

Maximum

Maximum

Integrity

Integrity

Protected

Protected Data

Data Rate

Rate Uplink is

Uplink

a portion of the

Integrity

Protected Data

Rate in the

Uplink, which

is enforced by

the S-NG-RAN

node for the

terminated

If the S-NG-

RAN node

Maximum

Integrity

Protected Data

Rate Downlink

IE is not

present, this IE

applies to both

UL and DL.

Bit Rate
The S-NG-
YES
reject

9.2.3.4
RAN node

Maximum

Maximum

Integrity

Integrity

Protected

Protected Data

Data Rate

Rate Downlink

is a portion of

the UE's

Maximum

Integrity

Protected Data

Rate in the

which is

enforced by

the S-NG-RAN

node for the

terminated

Location
O

ENUMERATE
Indicates that
YES
ignore

Information at

Location

reporting

Information at

S-NODE is to

be provided.

9.2.2.33
Information
YES
ignore

Resource

used to

Coordination

coordinate

Information

resource

utilisation

and S-NG-

Masked
O

YES
ignore

YES
ignore

Pattern

SN Addition
O

ENUMERATED
This IE
YES
reject

Trigger

(SN change,
indicates the

Indication

Preparation

procedure

Trace
O

YES
ignore

Activation

Requested
O

ENUMERATED
Indicates that
YES
ignore

Fast MCG

recovery via

for fast MCG

recovery via

SRB3 are

UE Radio
O

YES
reject

Capability ID

Source NG-
O

Global NG-
The NG-RAN
YES
ignore

RAN Node ID

RAN Node ID
Node ID of the

RAN node or

the source SN.

Management
O

YES
ignore

Based MDT

PLMN List

UE History
O

YES
ignore

Information

UE History
O

YES
ignore

Information

from the UE

ENUMERATED

YES
ignore

Change

History

IAB Node
O

ENUMERATED

YES
reject

Indication

No PDU
O

ENUMERATED
This IE applies
YES
ignore

Session

Indication

is an IAB-MT.

CHO
O

YES
reject

Information

SN Addition

RAN Node ID

node ID

node UE
the source M-

node UE

INTEGER

Arrival

Probability

SCG
O

YES
ignore

Activation

Request

Conditional
O

YES
reject

Addition

Information

Request

INTEGER
Indicates the
—

Number of

PSCells To

number of

Prepare

PSCells that

the target SN

may prepare.

INTEGER
Indicates the
—

Arrival

Probability

probability for

the UE

towards the

candidate

UE Slice
This IE
YES
reject

node UE

Maximum Bit
indicates the

Slice

Rate List
S-NG-RAN

Maximum Bit

9.2.3.167
node portion of

the UE Slice

Aggregate

Maximum Bit

Rate as

specified in TS

ENUMERATED
This IE applies
YES
reject

terminating

is an IAB-MT.

Indicator

Deactivation
O

Indication of

command

deactivation of

satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area
O

Service Area

to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

Deactivation of

satellite

For IEs according to the Table 17, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

According to an embodiment, the first message may be an S-node modification request message, and the second message may be an S-node modification response message. The satellite 620 may transmit the S-node modification request message to the base station 1220 through the XN interface. The base station 1220 may transmit the S-node modification response message to the satellite 620 through the XN interface. The S-node modification request message may include at least one of the information of the Table 7 and the Table 8. The S-node modification response message may include at least one of the information in the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 18.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message Type
M

YES
reject

M-NG-RAN node
M

NG-RAN
Allocated at
YES
reject

node UE
the M-NG-

XnAP ID
RAN node

S-NG-RAN node
M

NG-RAN
Allocated at
YES
reject

node UE
the S-NG-

XnAP ID
RAN node

Cause
M

YES
ignore

PDCP Change
O

YES
ignore

Indication

Selected PLMN

PLMN
The selected
YES
ignore

Identity
PLMN of the

9.2.2.4
SCG in the S-

Mobility Restriction
O

YES
ignore

SCG Configuration
O

YES
ignore

Query

UE Context

YES
reject

Information

>UE Security
O

Capabilities

node Security

node UE

Aggregate

Aggregate

Maximum Bit

Maximum Bit

>Index to
O

Selection Priority

>Lower Layer
O

presence status

change

Resources To

Be Added List

Session

neither the

Resources To

PDU Session

Be Added Item

Resource

Setup Info -

SN terminated

nor the

PDU Session

Resource

Setup Info -

terminated IE

is present in a

PDU Session

Resources To

Be Added

abnormal

conditions as

specified in

Session ID

PDU Session

RAN node

Aggregate

PDU Session

Maximum Bit

Aggregate

Maximum Bit

Session

Resource

Setup Info -

SN terminated

Session

Resource

Setup Info -

terminated

Expected UE
Expected UE
YES
ignore

Session

Activity
Activity

Expected UE

Behaviour
Behaviour for

Activity

9.2.3.82
the PDU

Behaviour

Resources To

Be Modified List

Session

neither the

Resources To

PDU Session

Be Modified

Resource

Modification

Info - SN

terminated IE

nor the

PDU Session

Resource

Modification

Info - MN

terminated IE

is present in a

PDU Session

Resources To

Be Modified

abnormal

conditions as

specified in

Session ID

PDU Session

RAN node

Aggregate

PDU Session

Maximum Bit

Aggregate

Maximum Bit

Session

Resource

Modification

Info - SN

terminated

Session

Resource

Modification

Info - MN

terminated

YES
reject

Expected UE
Expected UE
YES
ignore

Session

Activity
Activity

Expected UE

Behaviour
Behaviour for

Activity

9.2.3.82
the PDU

Behaviour

>PDU Session
O

PDU session

Resources To Be

List with

Released List

Cause

M-NG-RAN node
O

OCTET
Includes the
YES
ignore

to S-NG-RAN

node Container

message as

defined in

11.2.2. of TS

Requested Split
O

ENUMERATED
Indicates that
YES
ignore

(srb1, srb2,
resources for

are requested.

Requested Split
O

ENUMERATED
Indicates that
YES
ignore

SRBs release

(srb1, srb2,
resources for

are requested

to be

Desired Activity
O

YES
ignore

Notification Level

Additional DRB
O

DRB List
Indicates
YES
reject

9.2.1.29
additional list

of DRB IDs

that the S-

node may use

for SN-

terminated

S-NG-RAN node
O

Bit Rate
The S-NG-
YES
reject

Maximum Integrity

9.2.3.4
RAN node

Protected Data

Maximum

Rate Uplink

Integrity

Protected

Data Rate

Uplink is a

portion of the

Integrity

Protected

Data Rate in

the Uplink,

which is

enforced by

the S-NG-

RAN node for

the UE's SN

terminated

sessions. If

the S-NG-

RAN node

Maximum

Integrity

Protected

Data Rate

Downlink IE is

not present,

this IE applies

to both UL

and DL.

S-NG-RAN node
O

Bit Rate
The S-NG-
YES
reject

Maximum Integrity

9.2.3.4
RAN node

Protected Data

Maximum

Rate Downlink

Integrity

Protected

Data Rate

Downlink is a

portion of the

Integrity

Protected

Data Rate in

the Downlink,

which is

enforced by

the S-NG-

RAN node for

the UE's SN

terminated

Location
O

ENUMERATED
Indicates that
YES
ignore

Information at S-

NODE reporting

Location

Information at

S-NODE is to

be provided.

MR-DC Resource
O

9.2.2.33
Information
YES
ignore

Coordination

used to

Information

coordinate

resource

utilisation

node and S-

PCell ID
O

Global NG -

YES
reject

RAN Cell

Identity

YES
ignore

Pattern

Requested Fast
O

ENUMERATED
Indicates that
YES
ignore

MCG recovery via

for fast MCG

recovery via

SRB3 are

Requested Fast
O

ENUMERATED
Indicates that
YES
ignore

MCG recovery via

fast MCG

recovery via

SRB3 are

requested to

be released.

SN triggered
O

ENUMERATED

YES
ignore

Target Node ID
O

Global NG-
Indicates the
YES
ignore

RAN Node ID
target node ID

9.2.2.3
of the

handover

procedure

decided by

the M-NG-

PSCell History
O

ENUMERATED
Indicates that
YES
ignore

Information

Retrieve

history

information is

UE History
O

YES
ignore

Information from

the UE

CHO Information
O

YES
ignore

SN Modification

ENUMERATED

Reconfiguration

INTEGER

Arrival

Probability

SCG Activation
O

YES
ignore

Request

Conditional
O

This IE may
YES
ignore

be sent to the

Information

Modification

Request

INTEGER
Indicates the
—

Number of

PSCells To

number of

Prepare

PSCells that

the target SN

may prepare.

INTEGER
Indicates the

Arrival

Probability

probability for

the UE

towards the

candidate

Conditional
O

This IE may
YES
ignore

be sent to the

Information

Update

RAN Node

RAN Node ID

NR CGI

S-NG-RAN node
O

UE Slice
This IE
YES
ignore

UE Slice

Maximum Bit
indicates the

Maximum Bit Rate

Rate List
S-NG-RAN

9.2.3.167
node portion

of the UE

Slice

Aggregate

Maximum Bit

Rate as

specified in

Management
O

YES
ignore

Based MDT PLMN

Modification

Modification List

Deactivation
O

Indication of

command

of satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area
O

Service Area

to be

other ID)

Frequency Band
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

of satellite

For IEs according to the Table 18, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

According to an embodiment, the first message may be an S-node modification demand message, and the second message may be an S-node modification confirmation message. The satellite 620 may transmit the S-node modification demand message to the base station 1220 through the XN interface. The base station 1220 may transmit an S-node modification confirmation message to the satellite 620 through the XN interface. The S-node modification demand message may include at least one of the information of the Table 7 and the Table 8. The S-node modification confirmation message may include at least one of the information of the Table 7 and the Table 8. For example, the first message may include the following IEs as exemplified in Table 19.

IE type and
Semantics

Assigned

IE/Group Name
Presence
Range
reference
description
Criticality
Criticality

Message
M

YES
reject

NG-RAN node UE
Allocated at
YES
reject

node UE

XnAP ID
the M-NG-

9.2.3.16
RAN node

NG-RAN node UE
Allocated at
YES
reject

node UE

XnAP ID
the S-NG-

9.2.3.16
RAN node

Cause
M

YES
ignore

PDCP
O

YES
ignore

Change

Indication

YES
ignore

Session

Resources

To Be

Modified

Session

neither the

Resources

PDU Session

To Be

Resource

Modified

Modification

Required Info -

terminated IE

nor the

PDU Session

Resource

Modification

Required Info -

terminated IE

is present in

a PDU

Session

Resources

To Be

Modified Item

conditions as

specified in

clause

Session

Session

Resource

Modification

Required

Info - SN

terminated

Session

Resource

Modification

Required

Info - MN

terminated

YES
ignore

Session

Resources

To Be

Released

Session

Resources

To Be

Released

PDU session List with

sessions

data forwarding

to be

request info

released

List - SN

terminated

PDU session List with

sessions

Cause

to be

released

List - MN

terminated

OCTET STRING
Includes the
YES
ignore

node to M-

message or

the CG-

Container

message as

defined in

11.2.2 of TS

Spare DRB
O

DRB List
Indicates the
YES
ignore

9.2.1.29
list of

unnecessary

DRB IDs that

had been

used by the

Required
O

Number of DRBs
Indicates the
YES
ignore

Number of

9.2.3.78
number of

DRB IDs

DRB IDs that

the S-NG-

RAN node

requests

Location
O

Target Cell Global ID
Contains
YES
ignore

Information

9.2.3.25
information

at S-NODE

to support

localisation

of the UE

9.2.2.33
Information
YES
ignore

Resource

used to

Coordination

coordinate

Information

resource

utilisation

node and S-

RRC Config
O

YES
reject

Indication

SCG
O

YES
ignore

Indicator

SCG UE
O

Yes
ignore

History

Information

SCG
O

YES
ignore

Activation

Request

CPAC
O

This IE may
YES
ignore

Information

be sent from

Required

the target SN.

Indicates the
—

full list of

candidate

prepared at

the target S-

SCG
O

ENUMERATED

YES
ignore

Reconfiguration

Notification

Deactivation
O

Indication of

command

of satellite

Cell list
O

Indication of

cells to be

DRB ID
O

Indication of

DRBs to be

SRB ID
O

Indication of

SRBs to be

Timer
O

Timer

gNB DU ID
O

DU to be

Service Area
O

Service Area

to be

other ID)

Frequency
O

Frequency

band to be

Area Type
O

Service Area

Cause
O

Cause of

of satellite

For IEs according to the Table 19, the Table 7 for the deactivation indication and the 3GPP TS 38.423 standard may be referenced.

FIG. 13 illustrates an example of components of a satellite (e.g., the satellite 260 or the satellite 620). The terms ‘ . . . unit’, ‘ . . . device’, and the like, used hereinafter mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

Referring to FIG. 13, the satellite 620 may include a transceiver 1301, a processor 1303, and memory 1305. The transceiver 1301 performs functions for transmitting and receiving a signal through a wireless channel. For example, the transceiver 1301 up-converts a baseband signal into an RF band signal and then transmits it through an antenna, and down-converts the RF band signal received through the antenna into the baseband signal. For example, the transceiver 1301 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

The transceiver 1301 may include a plurality of transmission/reception paths. Furthermore, the transceiver 1301 may include an antenna unit. The transceiver 1301 may include at least one antenna array configured with a plurality of antenna elements. In terms of hardware, the transceiver 1301 may be configured with a digital circuit and an analog circuit (e.g., a radio frequency integrated circuit (RFIC)). Herein, the digital circuit and the analog circuit may be implemented as one package. In addition, the transceiver 1301 may include a plurality of RF chains. The transceiver 1301 may perform beamforming. The transceiver 1301 may apply a beamforming weight to a signal in order to assign directivity to the signal to be transmitted and received according to a setting of the processor 1303. According to an embodiment, the transceiver 1301 may include a radio frequency (RF) block (or a RF unit).

The transceiver 1301 may transmit and receive a signal on a radio access network. For example, the transceiver 1301 may transmit a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., a cell-specific reference signal (CRS) and a demodulation (DM)-RS), system information (e.g., a MIB, a SIB, and remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data. In addition, for example, the transceiver 1301 may receive an uplink signal. The uplink signal may include a random access related signal (e.g., a random access preamble (RAP) (or a message 1 (Msg 1)), or a message 3 (Msg 3)), a reference signal (e.g., a sounding reference signal (SRS), or a DM-RS), or a power headroom report (PHR). Only the transceiver 1301 is illustrated in FIG. 13, but according to another implementation example, the satellite 620 may include two or more RF transceivers.

The processor 1303 controls overall operations of the satellite 620. The processor 1303 may be referred to as a control unit. For example, the processor 1303 transmits and receives a signal through the transceiver 1301. Furthermore, the processor 1303 writes and reads data to the memory 1305. Additionally, the processor 1303 may perform functions of a protocol stack required by a communication standard. Only the processor 1303 is illustrated in FIG. 13, but according to another implementation example, the satellite 620 may include two or more processors. The processor 1303, which is an instruction set or a code stored in the memory 1305, may be a storage space that stores an instructions/code or an instructions/code that are temporarily resided in the processor 1303, or may be part of circuitry constituting the processor 1303. In addition, the processor 1303 may include various modules for performing communication. The processor 1303 may control the satellite 620 to perform operations according to embodiments.

The memory 1305 stores data such as a basic program, an application program, setting information, and the like, for an operation of the satellite 620. The memory 1305 may be referred to as a storage unit. The memory 1305 may be configured with volatile memory, non-volatile memory, or a combination of the volatile memory and the non-volatile memory. Additionally, the memory 1305 provides stored data according to a request of the processor 1303. According to an embodiment, the memory 1305 may include memory for a condition, a command, or a setting value related to an SRS transmission method.

FIG. 14 illustrates an example of components of a terminal (e.g., UE 610). The terminal exemplifies the UE 610. The UE 610 may perform access to a gNB (e.g., the gNB 120) that provides NR access through an NTN.

Referring to FIG. 14, the UE 610 may include at least one processor 1401, at least one memory 1403, and at least one transceiver 1405. Hereinafter, a component is described in the singular, but implementation of a plurality of components or sub-components is not excluded.

The processor 1401 controls overall operations of the UE 610. For example, the processor 1401 writes and reads data to the memory 1403. For example, the processor 1401 transmits and receives a signal through the transceiver 1405. One processor is illustrated in FIG. 14, but embodiments of the present disclosure are not limited thereto. The UE 610 may include at least one processor to perform embodiments of the present disclosure. The processor 1401 may be referred to as a control unit or a control means. According to embodiments, the processor 1401 may control the UE 610 to perform at least one of operations or methods according to embodiments of the present disclosure.

The memory 1403 may store data such as a basic program, an application program, and setting information for an operation of the UE 610. The memory 1403 may store various data used by at least one component (e.g., the transceiver 1405 or the processor 1401). The data may include, for example, input data or output data for software and commands related thereto. The memory 1403 may be configured with volatile memory, nonvolatile memory, or a combination of the volatile memory and the nonvolatile memory. Additionally, the memory 1403 may provide stored data according to a request of the processor 1401.

The transceiver 1405 performs functions for transmitting and receiving a signal through a wireless channel. For example, the transceiver 1405 performs a conversion function between a baseband signal and a bit stream according to a physical layer specification of a system. For example, when transmitting data, the transceiver 1405 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the transceiver 1405 restores a reception bit stream by demodulating and decoding the baseband signal. In addition, the transceiver 1405 up-converts the baseband signal into a radio frequency (RF) band signal and then transmits it through an antenna, and down-converts the RF band signal received through the antenna into the baseband signal.

To this end, the transceiver 1405 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. In addition, the transceiver 1405 may include a plurality of transmission/reception paths. Furthermore, the transceiver 1405 may include at least one antenna array configured with a plurality of antenna elements. In terms of hardware, the transceiver 1405 may be configured with a digital unit and an analog unit, and the analog unit may be configured with a plurality of sub-units according to operating power, operating frequency, and the like.

The transceiver 1405 transmits and receives a signal as described above. Accordingly, the transceiver 1405 may be referred to as a ‘transmission unit’, a ‘reception unit’, or a ‘transmission/reception unit’. In addition, in the following description, transmission and reception performed through a wireless channel, a backhaul network, an optical cable, Ethernet, or another wired path are used in a meaning of including processing as described above being performed by the transceiver 1405. According to an embodiment, the transceiver 1405 may provide an interface for performing communication with other nodes in a network. That is, the transceiver 1405 may convert a bit stream transmitted from the UE 610 to another node, for example, another access node, another base station, an upper node, a core network, and the like into a physical signal, and may convert a physical signal received from another node into a bit stream.

In describing embodiments of the present disclosure, terms and messages defined in 3GPP are used to describe a message between a satellite (e.g., the satellite 620) and a terminal (e.g., the UE 610), but embodiments of the present disclosure are not limited thereto. Terms and messages having a technical meaning equivalent to the above-described terms and messages may be replaced and used of course. Furthermore, a gNB, a gNB-CU, and a gNB-DU, as well as a gNB-CU-control plane (CP) (e.g., the C-plane in FIG. 3A) and a gNB-CU-user plane (UP) (e.g., the U-plane in FIG. 3B) may be used as a satellite. In addition, not only a satellite may be used as a base station (e.g., a gNB) or a part of a base station (e.g., a DU), but also a core network entity (e.g., an AMF 235) connected to a base station may be implemented as the satellite. For example, communication between the satellite 620 and the satellite operating as the AMF 235 may be defined. For example, logical nodes including the AMF 235 and the gNB 120 may be implemented in one satellite. As implemented in a software manner through network virtualization, separated logical nodes may be disposed in a satellite, which is one piece of hardware.

In embodiments, an apparatus of a satellite for providing a non-terrestrial network (NTN) access is provided. The apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the apparatus to transmit, to a terminal through the at least one transceiver, a message including information indicating whether transform precoding of downlink transmission is activated, generate downlink signals based on the information, and transmit, to the terminal through the at least one transceiver, the downlink signals. In a case that the information indicates that the transform precoding is activated, the downlink signals may be generated through discrete a fourier transform-spreading (DFT-S) orthogonal frequency division multiplexing (OFDM) scheme, and in a case that the information does not indicate that the transform precoding is activated, the downlink signals may be generated through a cyclic prefix (CP)-OFDM schemc.

For example, the instructions, when executed by the at least one processor, may cause the apparatus to receive, from the terminal, capability information indicating that the terminal supports the transform precoding of downlink transmission.

For example, the message may include physical downlink shared channel (PDSCH) configuration information related to a non-terrestrial network (NTN). The PDSCH configuration information may include information indicating whether the transform precoding for a PDSCH is activated, first modulation and coding scheme (MCS) table information, and second MCS table information. The first MCS table information may indicate a MCS table used in case that the transform precoding is activated. The second MCS table information may indicate an MCS table used in case that the transform precoding is not activated.

In embodiments, a terminal for communicating with a satellite in a non-terrestrial network (NTN) access is provided. The terminal may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the terminal to receive, from the satellite through the at least one transceiver, a message including information indicating whether transform precoding of downlink transmission is activated and receive, from the satellite through the at least one transceiver, downlink signals based on the information. In a case that the information indicates that the transform precoding is activated, the downlink signals may be received through a discrete fourier transform-spreading (DFT-S) orthogonal frequency division multiplexing (OFDM) scheme. In a case that the information does not indicate that the transform precoding is activated, the downlink signals may be received through a cyclic prefix (CP)-OFDM scheme.

For example, the instructions, when executed by the at least one processor, may cause the terminal to transmit, to the satellite, capability information indicating that the terminal supports the transform precoding of downlink transmission.

For example, the message may include physical downlink shared channel (PDSCH) configuration information related to a non-terrestrial network (NTN). The PDSCH configuration information may include information indicating whether the transform precoding for a PDSCH is activated, first modulation and coding scheme (MCS) table information, and second MCS table information. The first MCS table information may indicate a MCS table used in case that the transform precoding is activated. The second MCS table information may indicate an MCS table used in case that the transform precoding is not activated.

In embodiments, a network apparatus for performing a communication with a satellite for providing a non-terrestrial network (NTN) access is provided. The network apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the network apparatus to identify a plurality of satellites corresponding to a sector related to a specific area, identify a first satellite to be deactivated among the plurality of satellites, based on prediction information related to a specific time, and transmit, to the first satellite through the at least one transceiver, a message for indicating deactivation of the first satellite.

For example, the message may include at least one of information on a cell to be deactivated, information on a data radio bearer (DRB) to be deactivated, information on a signaling radio bearer (SRB) to be deactivated, information on a distributed unit (DU) to be deactivated, or information on a frequency band to be deactivated.

For example, the message may include information on a service area to be deactivated and information on a type of the service area. The service area to be deactivated may include at least one of an area specified by a tracking area identity (TAI), an area specified by a TAI list, an area specified by a tracking area code (TAC), or a space area indicating one of space of a celestial body. The type may indicate one of a plurality of types of the service area. The plurality of types may include at least one of a sea, a continent, an island, or a desert.

For example, the message may include information on a timer for deactivation. The timer may start from a time when the message is received, and in a case that the timer expires, a state of the satellite may change from an inactive state to an active state.

For example, the message may include information on a cause of deactivation. The cause may indicate one of a plurality of causes. The plurality of causes may include at least one of deactivation due to orbital movement, resource optimization, user inactivity, service area type, low traffic in the cell, or low traffic in the service area. For example, the network apparatus may be a network entity that operates as an access and mobility management function (AMF) or a central unit (CU).

For example, the instructions, when executed by the at least one processor, may cause the network apparatus to transmit, to the first satellite through the at least one transceiver, another control signal indicating an activation of the first satellite.

In embodiments, an apparatus of a satellite for providing a non-terrestrial network (NTN) access is provided. The apparatus may comprise memory storing instructions, at least one processor, and at least one transceiver. The instructions, when executed by the at least one processor, may cause the satellite to receive, from a network apparatus through the at least one transceiver, a message for indicating deactivation of the satellite, and in response to the message, deactivate at least one of components of the satellite. The deactivation of the satellite may be associated with a specific area and a specific time.

For example, the message may include at least one of information on a cell to be deactivated, information on a data radio bearer (DRB) to be deactivated, information on a signaling radio bearer (SRB) to be deactivated, information on a distributed unit (DU) to be deactivated, or information on a frequency band to be deactivated.

For example, the message may include information on a service area to be deactivated and information on a type of the service area. The service area to be deactivated may include at least one of an area specified by a tracking area identity (TAI), an area specified by a TAI list, an area specified by a tracking area code (TAC), or a space area indicating one of space of a celestial body. The type may indicate one of a plurality of types of the service area. The plurality of types may include at least one of a sea, a continent, an island, or a desert.

For example, the message may include information on a timer for deactivation. The timer may start from a time when the message is received, and in a case that the timer expires, a state of the satellite may change from an inactive state to an active state.

For example, the message may include information on a cause of deactivation. The cause may indicate one of a plurality of causes. The plurality of causes may include at least one of deactivation due to orbital movement, resource optimization, user inactivity, service area type, low traffic in the cell, or low traffic in the service area. For example, the network apparatus may be a network entity that operates as an access and mobility management function (AMF) or a central unit (CU).

For example, the instructions, when executed by the at least one processor, may cause the satellite to receive, from the network apparatus through the at least one transceiver, another control signal indicating activation of the first satellite, and activate at least one of the components of the satellite in response to the another control signal.

Methods according to embodiments described in claims or specifications of the present disclosure may be implemented as a form of hardware, software, or a combination of hardware and software.

In case of implementing as software, a computer-readable storage medium for storing one or more programs (software module) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to embodiments described in claims or specifications of the present disclosure.

Such a program (software module, software) may be stored in random access memory, a non-volatile memory including flash memory, read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, compact disc-ROM (CD-ROM), an optical storage device (digital versatile discs (DVDs) or other formats), or a magnetic cassette. Alternatively, it may be stored in memory configured with a combination of some or all of them. In addition, a plurality of configuration memories may be included.

Additionally, a program may be stored in an attachable storage device capable of being accessed through a communication network such as the Internet, Intranet, local area network (LAN), wide area network (WAN), or storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may also be connected to a device performing an embodiment of the present disclosure.

In the above-described specific embodiments of the present disclosure, components included in the disclosure are expressed in the singular or plural according to the presented specific embodiment. However, the singular or plural expression is selected appropriately according to a situation presented for convenience of explanation, and the present disclosure is not limited to the singular or plural components, and even components expressed in the plural may be configured in the singular, or a component expressed in the singular may be configured in the plural.

Meanwhile, specific embodiments have been described in the detailed description of the present disclosure, and of course, various modifications are possible without departing from the scope of the present disclosure.