Apparatus and method for supporting identification of onboard base station in wireless communication system

Abstract

According to at least one embodiment, a method for operating a next generation (NG) node B (gNB) mounted on a non-terrestrial satellite comprises the steps of: establishing a physical layer connection to a non-terrestrial network (NTN) gateway for an NG application protocol (NGAP) connection; establishing a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection; determining that the NGAP connection will be inoperative or unavailable; and transmitting, in response to the determination, a message indicating that the NGAP connection will be inoperative or unavailable.

Description

Device and method for supporting identification of an onboard base station in a wireless communication system

[0001] The following description relates to a wireless communication system and to a device and method for supporting identification of an onboard base station.

[0002] The 3rd generation partnership project (3GPP) is discussing a non-terrestrial network (NTN) that would enable connectivity between terrestrial and satellite systems on the same mobile platform.

[0003] These networks or segments of networks may utilize satellites in different constellations, for example, to carry transmission equipment relay nodes. Such satellites include low Earth orbit (LEO) satellites, which typically operate at altitudes of approximately 400 to 2,000 kilometers (km); medium Earth orbit (MEO) satellites, which typically operate at altitudes of 8,000 to 20,000 kilometers; and geostationary Earth orbit (GEO) satellites, which typically operate at altitudes of approximately 36,000 kilometers above the Earth's equator.

[0004] Early efforts in NTN development focused on mobile broadband (MBB) and Internet of Things (IoT) use cases that place a low communication and / or computing burden on the node equipment aboard the satellite.

[0005] The present disclosure relates to a technology that supports the use of satellite-borne node equipment in a 5G (5th generation) system. For example, one aspect of the present disclosure is to facilitate the identification or recognition of a next-generation (NG) Node B (gNode B, gNB), which is a satellite-borne gNB (e.g., a spaceborne gNB or a satellite-onboard gNB).

[0006] NTNs may incorporate regenerative payload architectures that utilize these gNBs. Because these architectures may present unique operational considerations, it may be important to recognize whether a particular gNB is carried by a satellite. This can be particularly important in NTN implementations that include mixed deployments (e.g., a combination of spaceborne gNBs and terrestrial gNBs).

[0007] The present disclosure relates to a device and method for identifying a base station carried by a satellite in a wireless communication system.

[0008] The present disclosure relates to a device and method for setting information indicating a spaceborne base station in a wireless communication system.

[0009] The present disclosure relates to a device and method for transmitting information indicating that a base station is a spaceborne base station in a wireless communication system.

[0010] The present disclosure relates to a device and method for identifying a satellite-mounted base station using node-level signaling in a wireless communication system.

[0011] The present disclosure relates to a device and method for identifying a satellite-mounted base station using UE-related signaling through a preset NG protocol connection in a wireless communication system.

[0012] The present disclosure relates to a device and method for determining that an NGAP connection is to be disabled or unavailable in a wireless communication system.

[0013] The present disclosure relates to a device and method for transmitting a message indicating that an NGAP connection is to be disabled or unavailable in a wireless communication system.

[0014] The technical objectives to be achieved in the present disclosure are not limited to those mentioned above, and other technical tasks not mentioned can be considered by a person having ordinary skill in the technical field to which the technical configuration of the present disclosure is applied from the embodiments of the present disclosure described below.

[0015] According to at least one embodiment, a method of operating a next generation (NG) Node B (gNB) onboard a non-terrestrial satellite comprises establishing a physical layer connection to a non-terrestrial network (NTN) gateway for an NG application protocol (NGAP) connection, establishing a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection, determining that the NGAP connection is to be nonoperational or unavailable, and in response to the determination, transmitting a message indicating that the NGAP connection is to be nonoperational or unavailable.

[0016] According to at least one embodiment, a method of operating a network node of a 5G core network (5GC) comprises establishing a transport layer protocol connection to a next generation (NG) Node B (gNB) mounted on a non-terrestrial satellite for an NG application protocol (NGAP) connection, the NGAP connection including a physical layer connection established between an NTN gateway and the gNB, and receiving a message from the gNB indicating that the NGAP connection is to be disabled or unavailable.

[0017] According to at least one embodiment, a next generation (NG) Node B (gNB) aboard a non-terrestrial satellite, the gNB comprising at least one transceiver and at least one processor, wherein the at least one processor controls to establish a physical layer connection to a non-terrestrial network (NTN) gateway for an NG application protocol (NGAP) connection, to establish a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection, to determine that the NGAP connection is to be disabled or unavailable, and to transmit a message indicating that the NGAP connection is to be disabled or unavailable based on the determination.

[0018] According to at least one embodiment, a communications device includes at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, direct operations, the operations being controllable to: establish a physical layer connection to a non-terrestrial network (NTN) gateway for an NG application protocol (NGAP) connection; establish a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection; determine that the NGAP connection is to be inoperative or unavailable; and in response to the determination, transmit a message indicating that the NGAP connection is to be inoperative or unavailable.

[0019] According to at least one embodiment, a non-transitory computer-readable medium storing at least one instruction comprises at least one instruction executable by a processor, the at least one instruction being capable of controlling a device to establish a physical layer connection to a non-terrestrial network (NTN) gateway for an NG application protocol (NGAP) connection, establish a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection, determine that the NGAP connection is to be inoperative or unavailable, and in response to the determination, transmit a message indicating that the NGAP connection is to be inoperative or unavailable.

[0020] The following effects may be achieved by embodiments based on the present disclosure.

[0021] The present disclosure can identify a spaceborn gNB in ​​a wireless communication system.

[0022] The effects that can be obtained from the embodiments of the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly derived and understood by those skilled in the art to which the technical configuration of the present disclosure is applied, from the description of the embodiments of the present disclosure below. In other words, unintended effects that result from implementing the configuration described in the present disclosure can also be derived by those skilled in the art from the embodiments of the present disclosure.

[0023] To aid in understanding the present disclosure, the accompanying drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain aspects of the present disclosure.

[0024] Figure 1 illustrates the structure of a new radio (NR) system.

[0025] Figure 2 illustrates the functional division between NG-RAN (next generation radio access network) and 5GC (5th generation core network).

[0026] Figures 3a and 3b illustrate the wireless protocol architecture of the NR system.

[0027] Figure 4 illustrates an example of an NTN for providing non-terrestrial NR access via a transparent payload architecture.

[0028] Figure 5 illustrates an example of an NTN for providing non-terrestrial NR access via a regenerative payload architecture.

[0029] FIG. 6 illustrates a procedure related to a satellite-mounted gNB according to at least one embodiment.

[0030] FIG. 7 illustrates a procedure of a method of operation of a next generation (NG) node B (gNB) mounted on a non-terrestrial satellite according to at least one embodiment.

[0031] FIG. 8 illustrates a procedure of an operation method of a network node of a 5GC (5G core network) according to at least one embodiment.

[0032] The technology described below can be applied to various wireless access systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, E-UTRA (evolved-UTRA), etc. IEEE 802.16m is an advanced version of IEEE 802.16e, providing backward compatibility with IRRR 802.16e-based systems. UTRA is a part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved UTRA). 3GPP LTE uses OFDM for the downlink (DL) and SC-FDMA for the uplink (UL). LTE-A (LTE-advanced) is an evolution of 3GPP LTE.

[0033] As more and more communication devices demand greater communication capacity, the need for enhanced mobile broadband (eMBB) communications, which are superior to current radio access technology (RAT), is growing. Furthermore, Machine Type Communications (MTC), which connects devices and objects to provide a variety of services anytime, anywhere, is also considered a key issue in next-generation communications. Furthermore, discussions are ongoing on designing communication systems that consider reliability- and delay-sensitive services and / or UEs. The introduction of next-generation RAs, such as eMBB, high-capacity MTC, and URLLC (ultra-reliable and low-latency communications), is being discussed. For convenience of explanation, these technologies may be referred to as NR or new RAT in this disclosure.

[0034] For clarity, this disclosure will primarily focus on 3GPP NR, but the technical ideas contained in this disclosure are not limited thereto.

[0035] In the present disclosure, the terms "setting and / or set" may be replaced with the terms "configuration and / or configure," and the two terms may be used interchangeably. Conditional expressions (e.g., "if," "in the event of," or "when," etc.) may be replaced with "based on that" or "in a state / status." In addition, the operation of user equipment (UE) and / or base station (BS) and the configuration of software (SW) and / or hardware (HW) may be derived and / or understood based on the satisfaction of relevant conditions. If the process on the receiving (or transmitting) side in signal transmission and / or reception between wireless communication devices (e.g., BS, UE, etc.) can be derived and / or understood from the process on the transmitting (or receiving) side, the description thereof may be omitted. For example, signal determination, generation, encoding, and / or transmission at the transmitting side may be understood as signal monitoring reception, decoding, and / or determination at the receiving side. When a UE performs (or does not perform) a certain operation, it may be interpreted to mean that the BS expects and / or assumes (or does not expect and / or assume) that the UE will perform the certain operation. When a BS performs (or does not perform) a certain operation, it may be interpreted to mean that the UE expects and / or assumes (or does not expect and / or assume) that the BS will perform a certain operation. In the following description, the classification and indexing of sections, embodiments, examples, options, methods, schemes, etc. are merely for convenience of description and do not necessarily imply that each constitutes an independent disclosure or must be implemented individually.Additionally, in the absence of an explicit conflict in describing each section, embodiment, example, option, method, and solution, it can be inferred or understood that at least some sections, embodiments, examples, options, methods, solutions, etc. can be combined and implemented or omitted when implemented.

[0036] Figure 1 illustrates the structure of the NR system.

[0037] Referring to FIG. 1, a next-generation radio access network (NG-RAN) may include a BS (20) that provides user plane and control plane protocol termination to a UE (10). For example, the BS (20) may include a next-generation Node B (gNB) and / or an evolved Node B (eNB). The UE (10) may be fixed or mobile. The UE (10) may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), or a wireless device. For example, the BS (20) may be a fixed station that communicates with the UE (10). The BS (20) may be referred to by other terms such as a base transceiver system (BTS), an access point, etc.

[0038] Figure 1 illustrates an example that includes only gNB. For example, Figure 1 may include only gNB as BS (20). BS (20) may be connected to each other via Xn interface. BS (20) may be connected to 5GC (5) via NG interface. thgeneration core network). Specifically, the BS (20) can be connected to the AMF (access and mobility management function) (30) through the NG-C interface and to the UPF (user plane function) (30) through the NG-U interface.

[0039] Figure 2 illustrates the functional division between NG-RAN and 5GC.

[0040] Referring to FIG. 2, the gNB may provide functions including inter-cell radio resource management (RRM), radio admission control, measurement configuration and provisioning, and dynamic resource allocation. The AMF may provide functions such as non-access stratum (NAS) security and idle mobility handling. The UPF may provide functions including mobility anchoring and protocol data unit (PDU) processing. The session management function (SMF) may provide functions including UE internet protocol (IP) address allocation and PDU session control.

[0041] Based on the three lowest layers of the open systems interconnection (OSI) reference model known in communication systems, the wireless protocol stack between the UE and the network can be divided into layer 1 (L1), layer 2 (L2), and layer 3 (L3). These layers are defined in pairs between the UE and the evolved UTRAN (E-UTRAN) for data transmission over the Uu interface. The physical (PHY) layer of L1 provides information transmission services on physical channels. The radio resource control (RRC) layer of L3 controls radio resources between the UE and the network. For this purpose, the RRC layer exchanges RRC messages between the UE and the eNB.

[0042] Figures 3a and 3b illustrate the wireless protocol architecture of an NR system. Specifically, Figure 3a illustrates the user plane wireless protocol architecture, and Figure 3b illustrates the control plane wireless protocol architecture. The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

[0043] Referring to Figures 3a and 3b, the PHY layer provides information transmission services to upper layers via physical channels. The PHY layer is connected to the media access control (MAC) layer via transport channels, and data is transmitted between the MAC layer and the PHY layer via these transport channels. Transport channels are classified based on the function of transmitting data over the wireless interface.

[0044] Data is transmitted over physical channels between different PHY layers, i.e., the PHY layers of the transmitter and receiver. The physical channels can be modulated using orthogonal frequency division multiplexing (OFDM), and time and frequency can be used as radio resources.

[0045] The MAC layer provides services to the upper layer, the radio link control (RLC) layer, through logical channels. The MAC layer provides the ability to map multiple logical channels to multiple transport channels. Furthermore, the MAC layer provides logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC sublayer provides data transmission services through logical channels.

[0046] The RLC layer performs concatenation, segmentation, and reassembly of RLC service data units (SDUs). To guarantee the various quality of service (QoS) requirements of each radio bearer (RB), the RLC layer provides three operating modes: transparent mode (TM), unacknowledged mode (UTM), and acknowledged mode (AM). AM RLC provides error correction through automatic repeat request (ARQ).

[0047] The RRC layer is defined only in the control plane and controls logical channels, transport channels, and physical channels in relation to the configuration, reconfiguration, and release of RBs. RBs refer to logical paths provided by L1 (PHY layer) and L2 (MAC layer, RLC layer, and Packet Data Convergence Protocol (PDCP) layer) for data transmission between the UE and the network.

[0048] The user plane functions of the PDCP layer include user data transmission, header compression, and encryption. The control plane functions of the PDCP layer include control plane data transmission and encryption and / or integrity protection.

[0049] The Service Data Adaptation Protocol (SDAP) layer is defined only in the user plane. The SDAP layer performs functions such as mapping between QoS flows and data radio bearers, and marking QoS flow identifiers (IDs) in DL and UL packets.

[0050] Radio Bearer (RB) establishment is the process of defining radio protocol layers and channel functions to provide a specific service, and setting specific parameters and operating methods. RBs can be categorized into two types: signal radio bearers (SRBs) and data radio bearers (DRBs). SRBs are used as paths for transmitting RRC messages in the control plane, while DRBs are used as paths for transmitting user data in the user plane.

[0051] If an RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is placed in the RRC_CONNECTED state, otherwise the UE is placed in the RRC_IDLE state. In NR, the RRC_INACTIVE state is additionally defined. A UE in the RRC_INACTIVE state can be disconnected from the eNB while maintaining the connection to the core network.

[0052] DL transport channels for transmitting data from the network to the UE include a broadcast channel (BCH) for transmitting system information and a DL shared channel (DL SCH) for transmitting user traffic or control messages. Traffic or control messages of DL multicast or broadcast services can be transmitted on the DL-SCH or the DL multicast channel (DL MCH). UL transport channels for transmitting data from the UE to the network include a random access channel (RACH) for transmitting initial control messages and a UL shared channel (US SCH) for transmitting user traffic or control messages.

[0053] As described above, the logical channels that are located on top of the transport channels and are mapped to the transport channels include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and a multicast traffic channel (MTCH).

[0054] Figure 4 illustrates an example of an NTN for providing non-terrestrial NR access via a transparent payload architecture.

[0055] These architectures utilize a non-regenerative payload, which is a platform mounted on a satellite and lacks onboard processing capabilities for demodulation / decoding, switching and / or routing, coding / modulation, etc. Non-regenerative payloads operate similarly to analog radio frequency (RF) repeaters. They convert the frequency carrier of a received uplink RF signal, filter and amplify the signal, and then transmit it on the downlink. This means that only RF processing, such as frequency conversion, amplification, and beam management, can be performed on the satellite.

[0056] Continuing with reference to FIG. 4, the non-playback payload (402) is carried by a satellite. The non-playback payload (402) receives a wireless protocol from the UE, for example, via a service link (412). The non-playback payload (402) may perform frequency conversion, filtering, and amplification functions as previously mentioned. After performing these functions, the non-playback payload (402) may transparently transmit the resulting signal to a terrestrial NTN gateway (404) via a feeder link (414).

[0057] Similarly, the non-playback payload (402) can receive wireless protocols from the NTN gateway (404) via the feeder link (414). The non-playback payload (402) can perform the aforementioned frequency conversion, filtering, and amplification functions. After performing these functions, the non-playback payload (402) can transparently transmit the resulting signal to, for example, the UE via the service link (412).

[0058] The NG interface termination of NG-RAN, which provides NTN services using 5GC, can be understood as similar to a terrestrial network.

[0059] When performing the aforementioned functions, the non-playback payload (402) merely acts as an RF repeater. Therefore, a relatively light communication / computational burden is imposed on the non-playback payload (402).

[0060] With respect to the transparent payload architecture of Fig. 4, the following features have been addressed: mitigation of long propagation delays and reduced uplink coverage over the Uu interface, large beam footprint and wide cell coverage (which may span multiple countries) of the transparent payload, mobility issues, accommodation of large Doppler shifts, ensuring seamless service continuity over terrestrial networks due to time-varying cell coverage and gaps, and expansion of NTN operating frequency bands (e.g., service coverage and / or capacity expansion).

[0061] The present disclosure relates to an NTN that utilizes a regenerative payload architecture (e.g., instead of, or in addition to, a transparent payload architecture). Unlike the non-regenerative payload (402) of FIG. 4, the payload of the regenerative payload architecture can perform processes typically performed by a base station (e.g., modulation / demodulation, encoding / decoding, switching / routing, management of NG / Xn interfaces and UE contexts, RRM, etc.). Thus, decoding and processing of packets can be performed at the satellite. These functions are in addition to the RF processing capabilities described above with respect to the non-regenerative payload (402) of FIG. 4.

[0062] The replay payload architecture, which provides lower latency and much higher performance capabilities over the Uu interface, aims to further expand NTN service capabilities and service areas for more advanced use cases.

[0063] Figure 5 illustrates an example NTN for providing non-terrestrial NR access via a regenerative payload architecture. The regenerative payload architecture utilizes one or more regenerative payloads (e.g., gNB 502, gNB 522) mounted on one or more satellites. The regenerative payloads implement the function of regenerating signals received from Earth.

[0064] Referring to FIG. 5, the NR-Uu radio interface is provided on a service link (512) between the UE (506) and the gNB (502). A satellite radio interface (SRI) is provided between the gNB (502) and the NTN gateway (504). The NTN gateway (504) is a transport network layer node and supports all necessary transport protocols. The SRI includes a feeder link between the gNB (502) and the NTN gateway (504). The gNB (502) may be connected to the 5GC (508) via the NG interface (514).

[0065] Similarly, the NR-Uu radio interface is provided on the service link (532) between the UE (526) and the gNB (522). The SRI is provided between the gNB (522) and the NTN gateway (524). The NTN gateway (524) is a transport network layer node and supports all necessary transport protocols. The SRI includes a feeder link between the gNB (522) and the NTN gateway (524). The gNB (522) may be connected to the 5GC (528) via the NG interface (534).

[0066] Continuing with reference to FIG. 5, each satellite carrying a gNB (502) and a gNB (522) can communicate via an Xn interface via an inter-satellite link (ISL) (540) between satellites. The ISL is a transmission link between satellites. For example, the ISL (540) can be a wireless interface or an optical interface.

[0067] The regenerative payload architecture of FIG. 5, including spaceborne gNBs, can be utilized to enhance NTN capabilities. The present disclosure relates to techniques for supporting the use of regenerative payloads. For example, certain aspects of the present disclosure are directed to facilitating the identification or recognition of satellite-borne gNBs (e.g., gNBs 502 and 522). Facilitating the identification or recognition of satellite-borne gNBs can be accomplished via one or more messages transmitted from NR and / or NG-RAN.

[0068] The replay payload architecture may introduce issues that do not arise in the transparent payload architecture of Figure 4. For example, NG application protocol (NGAP) functions may be limited due to longer NG interface latency, connectivity variations, and space-related constraints.

[0069] Regarding interface latency, because the gNB is onboard the satellite, communication via the NG interface (e.g., a feeder link via the NTN Gateway (504)) is expected to experience longer latency. This latency did not occur in the transparent payload architecture, where the NG interface termination with the 5GC is located on the ground, similar to a terrestrial network. Therefore, in the replay payload architecture, the relevant timers for the NGAP need to be adjusted and / or applied differently.

[0070] With regard to connectivity changes, the NG connectivity of a Spaceborne gNB is difficult to handle similarly to the legacy NG connectivity of a gNB in ​​a terrestrial network or the NG connectivity of a ground-based NTN gNB (of a transparent payload). In a regenerative payload architecture, the NG connectivity must be through space (e.g., via a feeder link or ISL (540)). This can lead to issues related to frequent and dynamic changes in connectivity with the NTN Gateway (e.g., loss of line-of-sight to a first NTN Gateway and appearance or reappearance of line-of-sight to a second NTN Gateway at a different location depending on the satellite orbit) and increased potential for communication disruptions.

[0071] Regarding NGAP feature limitations, not all NGAP features may be supported on Spaceborne gNBs due to power and / or processing power constraints, as well as limited feeder link transport capability. For example, Spaceborne gNBs have limited feeder link transport capability compared to terrestrial network or transparent payload architecture gNBs, which may prevent them from supporting some NGAP features.

[0072] On the other hand, as propagation delays through the Uu interface decrease, features that were developed for transparent payloads to alleviate issues with the Uu interface (e.g., service link (412) in FIG. 4) may no longer be necessary.

[0073] One aspect of the present disclosure is to easily distinguish spaceborne gNBs from non-satellite-borne gNBs in a 5G system. Non-satellite-borne gNBs include NTN gNBs supporting transparent payload architectures and gNBs in purely terrestrial systems. This is particularly important in mixed deployments that include both non-satellite-borne gNBs and spaceborne gNBs. As previously described, regenerative payload architectures can introduce challenges related to longer NG interface latency, connectivity variations, and potentially limited NGAP functionality due to space-related constraints. These challenges can be addressed by recognizing that a particular gNB is satellite-borne.

[0074] However, according to 3GPP specifications, there is no mechanism to enable such differentiation in 5G systems. For example, the RAT type information provided by tracking area via NGAP does not specify whether a specific gNB is carried by a satellite or supports NTN services on the ground based on a transparent payload architecture. Therefore, during 5G system operation, the former type of gNB and the latter type of gNB cannot be easily distinguished or recognized.

[0075] Aspects of the present disclosure relate to mechanisms that facilitate the identification of a gNB as a spaceborne gNB in ​​a 5G system. Aspects of the present disclosure may be described below in relation to node-level signaling. Furthermore, aspects of the present disclosure relate to UE-related signaling.

[0076] First, we will describe the former type of gNB in ​​detail. In this regard, node-level signaling can be configured or provided to the Spaceborn gNB. Alternatively or additionally, node-level signaling can be initiated by the Spaceborn gNB.

[0077] For example, according to at least one embodiment, after a physical layer and / or transport network layer connection with a 5GC is successfully established, the spaceborn gNB may initiate NGAP connection setup using information indicating that the gNB is a spaceborn gNB. These and other features will be described in more detail with reference to FIG. 6.

[0078] FIG. 6 illustrates procedures related to a spaceborne gNB (e.g., a satellite-mounted gNB), an adjacent NTN gNB, an NTN gateway, a 5GC, and operation, administration, maintenance (OAM) according to at least one embodiment.

[0079] Prior to deploying a gNB that will be in Earth orbit, information related to a dedicated specific transport layer protocol for NGAP signaling may be pre-configured in the gNB (e.g., gNB (502) of FIG. 5). For example, the information related to a dedicated specific transport layer protocol for NGAP signaling may include a destination IP address, a port number, or a payload protocol identifier (PPID) when stream control transmission protocol (SCTP) is used. The gNB may be pre-configured with a specific gNB ID that identifies it as a spaceborne gNB. This ID may be one of multiple IDs specifically reserved for gNBs that are or will be in Earth orbit.

[0080] According to at least one embodiment, such information may be preset in the satellite-mounted gNB by OAM before the satellite carrying the gNB is deployed (e.g., step S602 of FIG. 6 ).

[0081] Alternatively, this information may be communicated to the adjacent NTN gNB (e.g., step S604 of FIG. 6). In step S606, after the deployment of the spaceborn gNB (e.g., gNB (502) of FIG. 5), the information as described above may be set to the spaceborn gNB via the Xn-connected adjacent NTN gNB (e.g., gNB (522)).

[0082] In step S608, the spaceborn gNB (e.g., gNB (502) of FIG. 5) establishes a physical layer connection to or with an NTN gateway (e.g., NTN gateway (504)). The physical layer connection may be established for an NGAP connection.

[0083] At step S610, the Spaceborn gNB establishes a transport layer protocol connection to or with the 5GC (e.g., AMF of 5GC (508) of FIG. 5) for setup of an NGAP connection. Here, if specific transport layer protocol-related information is standardized or pre-configured (e.g., step S602 or step S604), the information can be used by the 5GC to identify the gNB as a Spaceborn gNB.

[0084] When the transport network becomes operational with the 5GC (e.g., after a transport layer protocol connection is established), the Spaceborne gNB initiates NG connection setup. For example, at step S612, the satellite-mounted gNB sends a setup message (e.g., an NG SETUP REQUEST message) to the 5GC to initiate NGAP connection setup. The setup message may include information indicating or indicating that the gNB is a Spaceborne gNB.

[0085] For example, the NG setup request message may include a specific gNB ID related to steps S602 and S604 described above.

[0086] Alternatively, the NG setup request message may include an explicit indicator (e.g., a binary indicator) that can be recognized by the 5GC to indicate that the gNB is a spaceborn gNB.

[0087] Alternatively, the NG setup request message may include information regarding the feeder link availability time. This information may be recognized by the 5GC as indicating that the gNB is in space. As previously described with respect to the frequent and / or dynamic changes in connectivity with the NTN Gateway, line-of-sight to the NTN Gateway may be lost and regained over time due to the satellite's orbit (e.g., depending on its orbital trajectory). The feeder link availability time may be based on the pre-planned trajectory for the NG connection and the location and / or coverage of the NTN Gateway.

[0088] In step S614, the satellite-mounted gNB receives a response message (e.g., an NG SETUP RESPONSE message) from the 5GC in response to the setup message in step S612. The response message may indicate that the setup message has been received by the 5GC.

[0089] For the Spaceborne gNB, the AMF (of the 5GC) may initiate an update of NGAP application configuration data. For example, the update initiation may include sending a configuration message containing specific transport protocol layer-related information to be used by the satellite-mounted gNB for future NG connection setup. For example, this updated information may be used in place of similar information described above, referring to steps S602 and S604.

[0090] For example, at step S616, the Spaceborn gNB may receive a configuration message (e.g., an AMF CONFIGURATION UPDATE message) from the 5GC. The configuration message may include transport protocol layer related information to be used for future NGAP connections (e.g., target IP address, port number, payload protocol identifier (PPID) if stream control transmission protocol (SCTP) is used, etc.). This information may be for use in future transmissions of setup messages similar to the setup message described in step S612.

[0091] In step S618, the Spaceborn gNB sends an acknowledgment message to the 5GC in response to receiving the configuration message in step S616. The acknowledgment message may indicate that the configuration message has been received by the Spaceborn gNB.

[0092] During operation, the Spaceborn gNB may determine that the NGAP connection is nonoperational or unavailable. For example, this determination may be based on the feeder link availability time described in step S612. Accordingly, this determination may be based on known information regarding the pre-planned trajectory for the NG connection and the location and / or coverage of the NTN gateway(s).

[0093] Alternatively or additionally, the aforementioned decision may be based on measurements of feeder link quality and a comparison of these measurements against one or more thresholds. For example, the quality of the feeder link may degrade before the satellite's trajectory causes the NG connection with the NTN gateway to be lost. If the measured quality falls below one or more thresholds, the Spaceborne gNB may determine that the NGAP connection will be disabled or unavailable. These one or more thresholds may be preconfigured or updated by the 5GC.

[0094] Before the NG interface is disconnected (e.g., due to unavailability of a feeder link), the spaceborn gNB may initiate an NGAP procedure to inform the 5GC that the NG connection will be lost (see step S620 of FIG. 6). For example, in response to a determination that the NGAP connection will become inoperative or unusable, the spaceborn gNB sends a message (e.g., an NG CONNECTION LOST START message, an NG REMOVAL REQUEST message, or an NG SUSPEND REQUEST message) to the 5GC to indicate that the NGAP connection will become inoperative. For example, this message is sent to indicate that the NGAP connection will be lost, released, or suspended.

[0095] As a result of sending a message in step S620, the NG connection may be released or suspended.

[0096] When the transport network with the 5GC becomes operational again, the Spaceborn gNB may initiate an NGAP procedure to notify the 5GC that the NG connection has become available. This is to enable the NG connection to be reestablished or resumed. For example, at step S622, the Spaceborn gNB sends a message (e.g., an NG CONNECTION LOST STOP message, an NG SETUP REQUEST message, or an NG RESUME REQUEST message) to the 5GC in response to the transport network becoming operational again. Accordingly, the NG connection can be reestablished or resumed.

[0097] As previously described with respect to various embodiments (e.g., those described with reference to FIGS. 5 and 6), certain aspects of the present disclosure are directed to facilitating identification or recognition of a gNB as a spaceborne gNB via one or more messages transmitted from the NR and / or NG-RAN. In at least one embodiment, the 5GC may be configured to identify that the gNB is in space based on observations made by the 5GC. Such observations may support a determination that the gNB is in space.

[0098] For example, as previously described, NG connections from a satellite-borne gNB may be frequently or periodically released and / or re-established, suspended and / or resumed, due to satellite movement and the availability of feeder links with ground-based NTN gateway(s). These changes in NG connections may be initiated by the satellite-borne gNB.

[0099] The 5GC can be configured to recognize these activities as characteristics of a gNB operating in space and to identify that the gNB is in space based on these activities.

[0100] Below, aspects of the present disclosure with respect to UE-related signaling will be described in more detail.

[0101] This signaling can be performed in relation to UEs served by the Spaceborne gNB via an already established NG protocol connection. For example, after the physical layer, transport network layer, and NG protocol connections have been successfully established with the 5GC, the Spaceborne gNB can transmit information indicating that it is a satellite-mounted gNB. This information can be transmitted via UE-related signaling provided via the satellite.

[0102] According to at least one embodiment, such indications may be conveyed via NGAP signaling related to the PDU session of the UE, or via data of the UE transmitted from the gNB to the 5GC via NG-U. Accordingly, such indications may be transparently conveyed to appropriate entities or functions (e.g., SMF or UPF) of the 5GC that require differentiated handling of PDU sessions and / or QoS flows for the UE(s) served via the spaceborn gNB.

[0103] According to at least one embodiment, a message (e.g., an NGAP INITIAL UE MESSAGE) may include such an indication. Through this message, the initial location information of the UE is also provided to the 5GC. In a legacy (non-NTN) system, the connected cell, the selected PLMN, and the associated tracking area (i.e., a single tracking area) of the UE are transmitted to the 5GC. In an NTN system using transparent payload, the location information is extended to provide more than one tracking area associated with the connected cell. This is because the coverage of a single cell provided by a satellite may be wider and span multiple tracking areas. However, this extension alone does not specify whether a particular gNB is onboard a satellite or supports NTN services on the ground based on a transparent payload architecture.

[0104] In at least one embodiment, a message (e.g., an NGAP Initial UE message) informs the AMF that a particular gNB is onboard the satellite. Once the AMF recognizes that the gNB is onboard the satellite, the AMF may forward this information to other entities or functions within the 5GC, e.g., entities or functions that need to differentiate and handle services for UE(s) served via the Spaceborne gNB.

[0105] According to at least one embodiment, other NGAP UE related signaling messages may be used to convey such indications.

[0106] FIG. 7 illustrates a procedure of a method (700) of operating a gNB mounted on a non-terrestrial satellite according to at least one embodiment.

[0107] Information identifying the Spaceborne gNB may be pre-configured in the gNB prior to deployment of the non-terrestrial satellite. For example, the information identifying the Spaceborne gNB may include at least a specific gNB ID reserved for use by the Spaceborne gNB.

[0108] For example, 5GC can identify a gNB as a spaceborn gNB based on preset transport layer protocol-related information.

[0109] Alternatively or additionally, after deploying the non-terrestrial satellite, information indicating the Spaceborne gNB may be set in the gNB.

[0110] At block 702, a physical layer connection to the NTN gateway for NGAP connectivity is established.

[0111] For example, referring back to step S608 of FIG. 6, a gNB (e.g., gNB (502) of FIG. 5) establishes a physical layer connection to or with an NTN gateway (e.g., NTN gateway (504)). The physical layer connection may be established for an NGAP connection.

[0112] At block 704, a transport layer protocol connection to 5GC is established for NGAP connectivity.

[0113] For example, referring back to step S610 of FIG. 6, the gNB establishes a transport layer protocol connection to or with the 5GC (e.g., AMF of 5GC (508) of FIG. 5) to establish an NGAP connection.

[0114] At block 706, a setup message may be sent to the 5GC to initiate NGAP connection setup. The setup message includes information related to the Spaceborn gNB.

[0115] For example, referring back to step S612 of FIG. 6, the gNB sends a setup message (e.g., an NG SETUP REQUEST message) to the 5GC to initiate NGAP connection setup. The setup message may include information indicating or indicating that the gNB is a spaceborn gNB.

[0116] At block 708, in response to the setup message of block 706, a response message may be received from 5GC.

[0117] For example, referring back to step S614 of FIG. 6, the gNB receives a response message (e.g., an NG SETUP RESPONSE message) from the 5GC in response to the setup message of step S612. The response message may indicate that the setup message has been received by the 5GC.

[0118] At block 710, a configuration message may be received from the 5GC. The configuration message may include transport protocol layer related information for future NGAP connections.

[0119] For example, referring back to step S616 of FIG. 6, the gNB may receive a configuration message (e.g., an AMF CONFIGURATION UPDATE message) from the 5GC. The configuration message may include transport protocol layer-related information (e.g., target IP address, port number, or PPID if SCTP is used) that will be used for future NGAP connections.

[0120] At block 712, a confirmation message for the setup message of block 710 may be sent to 5GC.

[0121] For example, referring back to step S618 of FIG. 6, the gNB sends a confirmation message to the 5GC in response to receiving the setup message of S616. The confirmation message may indicate that the setup message has been received by the gNB.

[0122] At block 714, the NGAP connection is determined to be non-functional or unavailable.

[0123] For example, as described above with reference to FIG. 6, during operation, the gNB may determine that an NGAP connection is inoperative or unavailable. For example, this determination may be based on feeder link availability. Accordingly, this determination may be based on a pre-planned trajectory for the NG connection and known information regarding the location / coverage of the NTN gateway(s).

[0124] The decision may be based on at least one of the position information of a non-terrestrial satellite or the position information of one or more NTN gateways preset or updated by 5GC.

[0125] Alternatively or additionally, the decision may be based on at least one of the feeder link quality measurements or a corresponding threshold preset or updated by 5GC.

[0126] At block 716, a message is sent indicating that the NGAP connection is not operational or will be unavailable.

[0127] For example, referring back to step S620 of FIG. 6, the gNB sends a message (e.g., an NG Connection Loss Start message, an NG Clear Request message, or an NG Suspension Request message) to the 5GC to indicate that the NGAP connection is to become inoperable. For example, this message is sent to indicate that the NGAP connection is to be lost, released, or suspended.

[0128] At block 718, in response to the NGAP connection being operational or available, a message may be sent to the 5GC to resume the NGAP procedure. The message may indicate that the NGAP connection is operational or available, allowing the NGAP connection to be reestablished or resumed.

[0129] For example, referring back to step S622 of FIG. 6, the gNB sends a message (e.g., an NG connection loss stop message, an NG establishment request message, or an NG resume request message) to the 5GC in response to the transport network being operational again, so that the NG connection can be re-established or resumed.

[0130] FIG. 8 illustrates a procedure of a method of operation of a network node of a 5G core network (5GC) according to at least one embodiment.

[0131] At block 802, a transport layer protocol connection to the gNB is established for NGAP connectivity.

[0132] For example, referring back to step S610 of FIG. 6, the 5GC (e.g., AMF of 5GC (508) of FIG. 5) establishes a transport layer protocol connection to or with a gNB (e.g., gNB (502) of FIG. 5) for NGAP connection.

[0133] An NGAP connection involves a physical layer connection established between an NTN gateway (e.g., NTN gateway (504)) and a gNB.

[0134] At block 804, 5GC receives a message indicating that the NGAP connection is not operational or will become unavailable.

[0135] For example, referring back to S620 of FIG. 6, the 5GC receives a message from the gNB indicating that the NGAP connection is to become inoperable (e.g., an NG Connection Loss Start message, an NG Remove Request message, or an NG Suspend Request message).

[0136] This message may be received after the gNB determines that the NGAP connection is in a non-functional or unavailable state. For example, as described above with reference to Figure 6, the gNB may make this determination during operation. This determination may be based on feeder link availability. Accordingly, this determination may be based on the pre-planned trajectory and known information regarding the location and / or coverage of the NTN gateway for NG connectivity.

[0137] The decision may be based on at least one of the position information of a non-terrestrial satellite or the position information of one or more NTN gateways preset or updated by 5GC.

[0138] Alternatively or additionally, the decision may be based on one or more of the feeder link quality measurements or corresponding thresholds preset or updated by 5GC.

[0139] The embodiments described above are specific combinations of the components and features of the present disclosure. Each component or feature is to be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, some components and / or features may be combined to implement embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be rearranged. Some components or features of one embodiment may be included in another embodiment, and components or features may be replaced with related components or features of another embodiment. It is to be understood that claims not explicitly recited in the appended claims may be combined to form embodiments or incorporated as new claims by post-filing amendment.

[0140] It will be apparent to those skilled in the art that the present disclosure can be implemented in various specific forms within the scope of the present disclosure. Therefore, the detailed description set forth above should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0141] Embodiments of the present disclosure can be applied to various wireless access systems. Examples of various wireless access systems include the 3rd Generation Partnership Project (3GPP) or 3GPP2 systems.

[0142] The embodiments of the present disclosure can be applied not only to the various wireless access systems described above, but also to all technical fields that utilize these various wireless access systems. Furthermore, the proposed method can also be applied to mmWave and THz communication systems utilizing ultra-high frequency bands.

[0143] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.

Claims

1. In the method, A step in which a gNB mounted on a non-terrestrial satellite establishes a physical layer connection to a non-terrestrial network (NTN) gateway for NG application protocol (NGAP) connection; A step in which the gNB establishes a transport layer protocol connection to a 5G core network (5GC) for the NGAP connection; a step in which the gNB determines that the NGAP connection is to become inoperative or unavailable; and A method comprising, in response to said determination, transmitting a message indicating that said NGAP connection is to be disabled or unavailable.

2. In claim 1, The above message is sent to indicate that the NGAP connection is to be lost, released, or suspended.

3. In claim 1, A method wherein the above decision is based on at least one of the position information of the non-terrestrial satellite or the position information of one or more NTN gateways preset or updated by the 5GC.

4. In claim 1, A method wherein the above decision is based on at least one of the measurements of feeder link quality or the corresponding threshold values preset or updated by the 5GC.

5. In claim 1, After establishing the above transport layer protocol connection, a step of transmitting a setup message including information related to the spaceborn gNB to the 5GC to initiate NGAP connection setup; and A method further comprising the step of receiving a response message from the 5GC in response to the above setup message.

6. In claim 5, A step of receiving a configuration message including information related to a transport protocol layer for future NGAP connection from the 5GC; and A method further comprising the step of transmitting a confirmation message for the setup message to the 5GC in response to the setup message.

7. In claim 1, A method further comprising, in response to the NGAP connection becoming operational or available, initiating the NGAP procedure to send a message indicating that the NGAP connection is operational or available to the 5GC so that the NGAP connection can be re-established or resumed.

8. In claim 1, A method in which information indicating that the non-terrestrial satellite is a spaceborne gNB is preset in the gNB before the non-terrestrial satellite is deployed.

9. In claim 8, A method in which the information indicating that the above spaceborn gNB is a spaceborn gNB includes at least one specific gNB ID reserved for use of the spaceborn gNB.

10. In claim 1, A method in which information indicating a spaceborne gNB is set in the gNB after the above non-terrestrial satellite is deployed.

11. In claim 1, A method in which the gNB is identified as a spaceborn gNB by the above 5GC based on preset transport layer protocol related information.

12. In claim 11, A method wherein the preset transport layer protocol-related information includes at least one of a target IP address, a port number, or a payload protocol identifier (PPID) when stream control transmission protocol (SCTP) is used.

13. In the method, A step for a network node to establish a transport layer protocol connection to a next generation (NG) node B (gNB) mounted on a non-terrestrial satellite for a next generation application protocol (NGAP) connection, wherein the NGAP connection includes a physical layer connection established between an NTN gateway and a gNB; and A method comprising the step of the network node receiving a message from the gNB indicating that the NGAP connection is to be inoperative or unavailable.

14. In claim 13, After establishing the above transport layer protocol connection, further comprising the step of receiving a setup message for resuming the NGAP connection setup from the gNB, A method wherein the configuration message includes at least one of an indicator indicating that the gNB is a spaceborn gNB, at least one specific gNB ID reserved for the spaceborn gNB, or a feeder link availability time.

15. In claim 13, Further comprising a step of receiving information indicating that the gNB is a spaceborn gNB through the NGAP connection, The above information is received using UE related signaling.

16. In the next generation (NG) Node B (gNB), at least one transceiver; and Contains at least one processor, At least one processor, Establish a physical layer connection to a non-terrestrial network (NTN) gateway for NG application protocol (NGAP) connectivity, Establish a transport layer protocol connection to the 5G core network (5GC) for the above NGAP connection, If the above NGAP connection is determined to be non-functional or unavailable, In response to the above decision, the gNB controls to send a message indicating that the NGAP connection will become inoperative or unavailable.

17. In communication devices, At least one processor; At least one memory storing instructions that direct operations when executed by at least one processor, said operations comprising: A step of establishing a physical layer connection to a non-terrestrial network (NTN) gateway for NG application protocol (NGAP) connection; A step of establishing a transport layer protocol connection to a 5G core network (5GC) for the above NGAP connection; determining that the above NGAP connection will not work or will be unavailable; and In response to the above decision, a communication device controlling the transmission of a message indicating that the NGAP connection is to be rendered inoperable or unavailable.

18. In a non-transitory computer-readable medium storing at least one instruction, comprising at least one instruction executable by the processor, At least one of the above commands causes the device to: Establish a physical layer connection to a non-terrestrial network (NTN) gateway for NG application protocol (NGAP) connectivity, Establish a transport layer protocol connection to the 5G core network (5GC) for the above NGAP connection, If the above NGAP connection is determined to be non-functional or unavailable, In response to said determination, a computer-readable medium controlling transmission of a message indicating that said NGAP connection is to be rendered inoperable or unavailable.

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