Resource management method and apparatus in communication system including non-terrestrial network

Abstract

An operation method of a first terrestrial base station may comprise the steps of: receiving a first measurement report reported by a first terminal from a first satellite forming a first satellite cell; determining, by the first terminal, access to a second satellite cell formed by a second satellite connected to the first terrestrial base station; identifying, by the first satellite cell, n BWPs configured for the first terminal; attempting, by the second satellite cell, a configuration to enable a first BWP group of the n BWPs for a service of the first terminal; and transmitting, to the first satellite, first configuration information including information generated based on the determining step and information generated based on a result of the attempting step.

Description

Technical Field

[0001] The present invention relates to a resource management technology in a communication system, and more particularly, to a handover management technology for improving the efficiency of radio resource management when performing handover, cell switching, etc. Background Art

[0002] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide enhanced communication services compared to existing communication networks (e.g., long term evolution (LTE), LTE-Advanced (LTE-A), etc.). 5G communication networks (e.g., New Radio (NR) communication networks) can support not only frequency bands of 6 GHz or below, but also frequency bands of 6 GHz or above. That is, the 5G communication network can support the frequency range FR1 band and / or FR2 band. Compared with the LTE communication network, the 5G communication network can support a wide variety of communication services and scenarios. For example, the usage scenarios of the 5G communication network may include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc.

[0003] Compared with 5G communication networks, 6G communication networks can support a wide variety of communication services and scenarios. 6G communication networks can meet the requirements of ultra-performance, ultra-bandwidth, ultra-space, ultra-precision, ultra-intelligence and / or ultra-reliability. 6G communication networks can support various broadbands and can be applied to various usage scenarios (e.g., terrestrial communication, non-terrestrial communication, sidelink communication, etc.).

[0004] A communication network (e.g., a 5G communication network, a 6G communication network, etc.) can provide communication services to terminals located on the ground. Recently, the demand for communication services not only for the ground but also for non-ground aircraft, drones, and satellites has been increasing, and for this purpose, the technology of non-terrestrial networks (NTN) has been discussed. The non-terrestrial network can be implemented based on 5G communication technology, 6G communication technology, etc. For example, in a non-terrestrial network, communication between a satellite and a ground communication node or a non-terrestrial communication node (e.g., an aircraft, a drone, etc.) can be performed based on 5G communication technology, 6G communication technology, etc. In NTN, a satellite can perform the function of a base station in a communication network (e.g., a 5G communication network, a 6G communication network, etc.).

[0005] In a handover process in a terrestrial network (TN) environment, radio resources such as a bandwidth part (BWP) of a terminal requested to be handed over can be newly configured in a target base station, and information about the newly configured BWP can be delivered to the terminal through a serving base station. The terminal can use the provided BWP configuration information to continue a random access channel (RACH) process and a subsequent connection establishment process with the target base station. On the other hand, in the case of NTN, a handover may occur due to the movement of a satellite or an NTN cell rather than the movement of a terminal. Therefore, a handover in an NTN environment may be performed differently from a handover in a TN environment. For example, when a handover occurs due to a new satellite entering a service area of ​​an existing satellite, the new satellite may preferably maintain the same BWP configuration configured for the terminal by the existing satellite. Therefore, a handover technology that can improve the efficiency of BWP configuration and operation in an NTN environment may be required. Summary of the invention

[0006] Technical issues

[0007] The present invention is directed to providing a resource management method and apparatus for improving the efficiency of radio resource management when handover is performed in a communication system including a non-terrestrial network.

[0008] Technical Solution

[0009] A first exemplary implementation of an operating method of a first ground base station for achieving the above-mentioned purpose may include: receiving a first measurement report reported by a first terminal from a first satellite, the first satellite forming a first satellite cell connected to the first terminal; determining, based on the first measurement report, that the first terminal will be connected to a second satellite cell, the second satellite cell being formed by a second satellite connected to the first ground base station; identifying n bandwidth parts (BWPs) configured for the first terminal in the first satellite cell; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve the first terminal in the second satellite cell; and sending first configuration information to the first satellite, the first configuration information including first BWP configuration information generated based on a result of the attempt and information indicating that the first terminal is connected to the second satellite cell, wherein n is a natural number.

[0010] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP being successfully configured to serve the first terminal, generating first BWP configuration information, the first BWP configuration information including information indicating that a first BWP among n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

[0011] The operation method may further include: sending second configuration information to the first terminal, wherein the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

[0012] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and generating first BWP configuration information indicating a result of the BWP reconfiguration.

[0013] The first BWP group may include m BWPs, and the attempt may include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; in response to the k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, wherein m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

[0014] The m BWPs may be first to m-th BWPs selected from among n BWPs based on BWP indexes, and the first BWP configuration information may include corresponding indexes of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

[0015] The operation method may further include: sending third configuration information to the first terminal, wherein the third configuration information instructs the first terminal to perform a BWP reconfiguration process with the second satellite cell for nk BWPs except for k BWPs among the n BWPs.

[0016] A second exemplary implementation of an operating method of a first ground base station for achieving the above-mentioned purpose may include: receiving a handover request of a first terminal from a second ground base station connected to a first satellite, the first terminal being connected to a first satellite cell, the first satellite cell being formed by a first satellite connected to the first ground base station; accepting a handover of the first terminal to a second satellite cell formed by the first satellite based on the handover request; identifying n bandwidth parts (BWPs) configured for the first terminal in the first satellite cell based on the handover request; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve the first terminal in the second satellite cell; and sending a first response to the second ground base station, the first response including first BWP configuration information generated based on a result of the attempt and information indicating that the handover request of the first terminal is accepted, wherein n is a natural number.

[0017] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP being successfully configured to serve the first terminal, generating first BWP configuration information, the first BWP configuration information including information indicating that a first BWP among n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

[0018] The operation method may further include: sending second configuration information to the first terminal, wherein the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

[0019] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and generating first BWP configuration information indicating a result of the BWP reconfiguration.

[0020] The first BWP group may include m BWPs, and the attempt may include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; in response to the k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, wherein m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

[0021] The m BWPs may be first to m-th BWPs selected from among n BWPs based on BWP indexes, and the first BWP configuration information may include corresponding indexes of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

[0022] The operation method may further include: sending third configuration information to the first terminal, wherein the third configuration information instructs the first terminal to perform a BWP reconfiguration process with the second satellite cell for nk BWPs except for k BWPs among the n BWPs.

[0023] A third exemplary implementation of an operating method of a first ground base station for achieving the above-mentioned purpose may include: receiving a handover request of a first terminal from a second ground base station, the first terminal being connected to a first satellite cell, the first satellite cell being formed by a first satellite connected to the second ground base station; accepting a handover of the first terminal to a second satellite cell formed by a second satellite connected to the second ground base station based on the handover request; identifying n bandwidth parts (BWPs) configured for the first terminal in the first satellite cell based on the handover request; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve the first terminal in the second satellite cell; and sending a first response to the second ground base station, the first response including first BWP configuration information generated based on a result of the attempt and information indicating that the handover request of the first terminal is accepted, wherein n is a natural number.

[0024] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP being successfully configured to serve the first terminal, generating first BWP configuration information, the first BWP configuration information including information indicating that a first BWP among n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

[0025] The operation method may further include: sending second configuration information to the first terminal, wherein the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

[0026] The first BWP group may include a first BWP, and the attempt may include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; in response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and generating first BWP configuration information indicating a result of the BWP reconfiguration.

[0027] The first BWP group may include m BWPs, and the attempt may include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; in response to the k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, wherein m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

[0028] The m BWPs may be first to m-th BWPs selected from among n BWPs based on BWP indexes, and the first BWP configuration information may include corresponding indexes of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

[0029] Beneficial Effects

[0030] According to an exemplary embodiment of a resource management method and apparatus in a communication system including an NTN, a terminal connected to the NTN can move from a first satellite cell to a second satellite cell. Here, when the terminal moves from the first satellite cell to the second satellite cell, at least a portion of the BWP configured for the terminal in the first satellite cell can be configured identically in the second satellite cell. Since a BWP partially overlapping with a previously used BWP is configured during the cell mobility process of the terminal, the overhead of configuring the BWP and the signaling process for the BWP information can be significantly reduced. Accordingly, the efficiency of the cell mobility process of the terminal can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1a is a conceptual diagram illustrating a first exemplary embodiment of a non-terrestrial network.

[0032] Figure 1b is a conceptual diagram illustrating a second exemplary embodiment of a non-terrestrial network.

[0033] Figure 2a is a conceptual diagram illustrating a third exemplary embodiment of a non-terrestrial network.

[0034] Figure 2b is a conceptual diagram illustrating a fourth exemplary embodiment of a non-terrestrial network.

[0035] Figure 2c is a conceptual diagram illustrating a fifth exemplary embodiment of a non-terrestrial network.

[0036] Figure 3 is a block diagram illustrating a first exemplary embodiment of communication nodes constituting a non-terrestrial network.

[0037] Figure 4 is a block diagram illustrating a first exemplary embodiment of a communication node performing communications.

[0038] Figure 5a is a block diagram illustrating a first exemplary implementation of a transmit path.

[0039] Figure 5b is a block diagram illustrating a first exemplary implementation of a receive path.

[0040] Figure 6a is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack of a user plane in a non-terrestrial network based on a transparent payload.

[0041] Figure 6b is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack of a control plane in a non-terrestrial network based on a transparent payload.

[0042] Figure 7a is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack for a user plane in a non-terrestrial network based on a regenerative payload.

[0043] Figure 7b is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack for a control plane in a non-terrestrial network based on a regenerative payload.

[0044] Figure 8 is a conceptual diagram illustrating a difference in handover according to a cell type in a non-terrestrial network (NTN).

[0045] Fig. 9 is a sequence diagram illustrating an exemplary implementation of a handover procedure in a terrestrial network (TN).

[0046] Figures 10a to 10c is a conceptual diagram describing an exemplary implementation of handover in an NTN.

[0047] Fig.11a and Fig.11b is a conceptual diagram describing an exemplary embodiment of a feeder link switching method in an NTN.

[0048] Fig.12 is a conceptual diagram describing the difference between handover in TN and handover in NTN.

[0049] Fig.13 is a sequence diagram describing a first exemplary embodiment of a resource management method in a communication system.

[0050] Fig.14 is a sequence diagram describing a second exemplary embodiment of a resource management method in a communication system.

[0051] Fig.15 is a sequence diagram describing a third exemplary embodiment of a resource management method in a communication system. DETAILED DESCRIPTION

[0052] Although the present invention is capable of various modifications and alternative forms, specific embodiments thereof are shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that it is not intended to limit the present invention to the specific forms disclosed, but on the contrary, the present invention covers all modifications, equivalent forms and alternative forms falling within the spirit and scope of the present invention. Throughout the description of the figures, the same reference numerals refer to the same elements.

[0053] It will be understood that, although the terms first, second, etc. can be used herein to describe each element, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present invention, the first element can be referred to as the second element and similarly, the second element can be referred to as the first element. As used in this article, the term "and / or" includes any combination and all combinations of one or more related enumeration items.

[0054] In the present invention, “at least one of A and B” may mean “at least one of A or B” or “at least one of a combination of one or more of A and B”. Furthermore, in an exemplary embodiment of the present invention, “one or more of A and B” may mean “one or more of A or B” or “one or more of a combination of one or more of A and B”.

[0055] In the present invention, "(re)transmission" may mean "transmission", "retransmission" or "transmission and retransmission", "(re)configuration" may mean "configuration", "reconfiguration" or "configuration and reconfiguration", "(re)connection" may mean "connection", "reconnection" or "connection and reconnection", and "(re)access" may mean "access", "reaccess" or "access and reaccess".

[0056] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0057] The terms used in this article are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in this article, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. It will be further understood that when the terms "include" and / or "comprising" are used in this article, it is explained that there are described features, numerical values, steps, operations, elements, components or combinations thereof, but does not exclude the presence or addition of one or more other features, numerical values, steps, operations, elements, components and / or combinations thereof.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the field to which the present invention belongs. It will be further understood that terms (for example, terms defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted as an idealized or overly formal meaning unless explicitly defined as such in this article.

[0059] Hereinafter, the exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In order to promote overall understanding when describing the present invention, the same components in the accompanying drawings are represented by the same reference numerals, and repeated descriptions thereof will be omitted. In addition to the exemplary embodiments clearly described in the present invention, operations can also be performed according to the combination of the exemplary embodiments, the expansion of the exemplary embodiments and / or the modification of the exemplary embodiments. The execution of some operations can be omitted, and the execution order of the operations can be changed.

[0060] Even when describing a method performed at a first communication node among communication nodes (e.g., transmission or reception of a signal), the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when describing the operation of a user equipment (UE), a base station corresponding to the UE may perform an operation corresponding to the operation of the UE. Conversely, when describing the operation of a base station, a UE corresponding to the base station may perform an operation corresponding to the operation of the base station. In a non-terrestrial network (NTN) (e.g., a payload-based NTN), the operation of a base station may refer to the operation of a satellite, and the operation of a satellite may refer to the operation of a base station.

[0061] A base station may refer to a node B, an evolved node B (eNodeB), a next generation node B (gNodeB), a gNB, a device, an apparatus, a node, a communication node, a base transceiver station (BTS), a radio remote head (RRH), a transmission reception point (TRP), a radio unit (RU), a roadside unit (RSU), a radio transceiver, an access point, an access node, etc. A UE may refer to a terminal, a device, an apparatus, a node, a communication node, an end node, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, an on-board unit (OBU), etc.

[0062] In the present invention, signaling may be at least one of higher layer signaling, medium access control (MAC) signaling, or physical (PHY) signaling. A message for higher layer signaling may be referred to as a "higher layer message" or a "higher layer signaling message". A message for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message". A message for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message". Higher layer signaling may refer to the sending and receiving operations of system information (e.g., master information block (MIB), system information block (SIB)) and / or RRC messages. MAC signaling may refer to the sending and receiving operations of a MAC control element (CE). PHY signaling may refer to the sending and receiving operations of control information (e.g., downlink control information (DCI), uplink control information (UCI), and sidelink control information (SCI)).

[0063] In the present invention, “configure an operation (e.g., send an operation)” may mean “send configuration information (e.g., information element or parameter) of an operation and / or information indicating the execution of an operation with a signal”. “Configure an information element (e.g., parameter)” may mean “send a corresponding information element with a signal”. In the present invention, “signal and / or channel” may mean signal, channel, or “signal and channel”, and “signal” may be used to mean “signal and / or channel”.

[0064] The communication system may include at least one of a terrestrial network, a non-terrestrial network, a 4G communication network (e.g., a long term evolution (LTE) communication network), a 5G communication network (e.g., a new radio (NR) communication network), or a 6G communication network. Each of the 4G communication network, the 5G communication network, and the 6G communication network may include a terrestrial network and / or a non-terrestrial network. The non-terrestrial network may operate based on at least one communication technology of the LTE communication technology, the 5G communication technology, or the 6G communication technology. The non-terrestrial network may provide communication services in various frequency bands.

[0065] The communication network to which the exemplary embodiment is applied is not limited to the content described below, and the exemplary embodiment can be applied to various communication networks (e.g., 4G communication network, 5G communication network and / or 6G communication network). Here, the communication network can be used in the same sense as the communication system.

[0066] Figure 1a is a conceptual diagram illustrating a first exemplary embodiment of a non-terrestrial network.

[0067] like Figure 1a As shown, the non-terrestrial network (NTN) may include a satellite 110, a communication node 120, a gateway 130, a data network 140, etc. A unit including the satellite 110 and the gateway 130 may correspond to a remote radio unit (RRU). Figure 1a The NTN shown may be a transparent payload-based NTN. Satellite 110 may be a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, or an unmanned aircraft system (UAS) platform. The UAS platform may include a high altitude platform station (HAPS). The non-GEO satellite may be a LEO satellite and / or a MEO satellite.

[0068] The communication node 120 may include a communication node located at a ground location (e.g., a user equipment (UE) or a terminal) and a communication node located in a non-ground space (e.g., an aircraft, a drone). A service link may be established between the satellite 110 and the communication node 120, and the service link may be a radio link. The satellite 110 may be referred to as an NTN payload. The gateway 130 may support multiple NTN payloads. The satellite 110 may provide communication services to the communication node 120 using one or more beams. The footprint of the beam of the satellite 110 may be elliptical or circular.

[0069] In non-terrestrial networks, the following three types of service links can be supported.

[0070] - Earth-fixed: The service link may be provided by a beam that always continuously covers the same geographical area (eg, a geosynchronous orbit (GSO) satellite).

[0071] - quasi-earth-fixed: the service link may be provided by a beam covering one geographical area during a defined period and by a beam covering another geographical area during another period (e.g. a non-GSO (NGSO) satellite forming a steerable beam).

[0072] - Earth-moving: The service link may be provided by a beam moving over the surface of the Earth (eg, a NGSO satellite forming a fixed or non-steerable beam).

[0073] The communication node 120 may perform communication (e.g., downlink communication and uplink communication) with the satellite 110 using 4G communication technology, 5G communication technology, and / or 6G communication technology. Communication between the satellite 110 and the communication node 120 may be performed using an NR-Uu interface and / or a 6G-Uu interface. When supporting dual connectivity (DC), the communication node 120 may be connected to other base stations (e.g., base stations supporting 4G, 5G, and / or 6G functions) and the satellite 110, and perform DC operations based on technologies defined in 4G, 5G, and / or 6G technical specifications.

[0074] The gateway 130 may be located at a ground location, and a feeder link may be established between the satellite 110 and the gateway 130. The feeder link may be a radio link. The gateway 130 may be referred to as a "non-terrestrial network (NTN) gateway". The communication between the satellite 110 and the gateway 130 may be performed based on an NR-Uu interface, a 6G-Uu interface, or a satellite radio interface (SRI). The gateway 130 may be connected to the data network 140. There may be a "core network" between the gateway 130 and the data network 140. In this case, the gateway 130 may be connected to the core network, and the core network may be connected to the data network 140. The core network may support 4G communication technology, 5G communication technology, and / or 6G communication technology. For example, the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), and the like. Communication between the gateway 130 and the core network may be performed based on an NG-C / U interface or a 6G-C / U interface.

[0075] like Figure 1b As shown in the exemplary embodiment of FIG. 1 , in a transparent payload-based NTN, a “core network” may exist between the gateway 130 and the data network 140 .

[0076] Figure 1b is a conceptual diagram illustrating a second exemplary embodiment of a non-terrestrial network.

[0077] like Figure 1b As shown, the gateway can be connected to the base station, the base station can be connected to the core network, and the core network can be connected to the data network. Each of the base station and the core network can support 4G communication technology, 5G communication technology and / or 6G communication technology. The communication between the gateway and the base station can be performed based on the NR-Uu interface or the 6G-Uu interface, and the communication between the base station and the core network (e.g., AMF, UPF, SMF, etc.) can be performed based on the NG-C / U interface or the 6G-C / U interface.

[0078] Figure 2a is a conceptual diagram illustrating a third exemplary embodiment of a non-terrestrial network.

[0079] like Figure 2a As shown, the non-terrestrial network may include a first satellite 211, a second satellite 212, a communication node 220, a gateway 230, a data network 240, and the like. Figure 2aThe NTN shown may be an NTN based on a regenerated payload. For example, each of satellite 211 and satellite 212 may perform a regeneration operation (e.g., demodulation, decoding, re-encoding, re-modulation, and / or filtering operation) on a payload received from another entity (e.g., communication node 220 or gateway 230) and transmit the regenerated payload.

[0080] Each of satellite 211 and satellite 212 can be a LEO satellite, a MEO satellite, a GEO satellite, a HEO satellite or a UAS platform. The UAS platform can include a HAPS. Satellite 211 can be connected to satellite 212, and an inter-satellite link (ISL) can be established between satellite 211 and satellite 212. ISL can operate in RF band or optical band. ISL can be selectively established. Communication node 220 can include ground communication nodes (e.g., UE or terminal) and non-ground communication nodes (e.g., aircraft or drone). A service link (e.g., radio link) can be established between satellite 211 and communication node 220. Satellite 211 can be referred to as NTN payload. Satellite 211 can provide communication services to communication node 220 using one or more beams.

[0081] The communication node 220 can perform communication (e.g., downlink communication or uplink communication) with the satellite 211 using 4G communication technology, 5G communication technology, and / or 6G communication technology. The communication between the satellite 211 and the communication node 220 can be performed using the NR-Uu interface or the 6G-Uu interface. When DC is supported, the communication node 220 can be connected to other base stations (e.g., base stations supporting 4G, 5G, and / or 6G functions) and the satellite 211, and can perform DC operations based on the technologies defined in the 4G, 5G, and / or 6G technical specifications.

[0082] The gateway 230 may be located at a ground location, a feeder link may be established between the satellite 211 and the gateway 230, and a feeder link may be established between the satellite 212 and the gateway 230. The feeder link may be a radio link. When an ISL is not established between the satellite 211 and the satellite 212, a feeder link between the satellite 211 and the gateway 230 may be established compulsorily. The communication between each of the satellite 211 and the satellite 212 and the gateway 230 may be performed based on an NR-Uu interface, a 6G-Uu interface, or an SRI. The gateway 230 may be connected to a data network 240.

[0083] like Figure 2b and Figure 2c As shown in the exemplary embodiment of FIG. 2 , a “core network” may exist between gateway 230 and data network 240 .

[0084] Figure 2b is a conceptual diagram showing a fourth exemplary embodiment of a non-terrestrial network, Figure 2c is a conceptual diagram illustrating a fifth exemplary embodiment of a non-terrestrial network.

[0085] like Figure 2b and Figure 2c As shown, the gateway can be connected to the core network, and the core network can be connected to the data network. The core network can support 4G communication technology, 5G communication technology and / or 6G communication technology. For example. The core network may include AMF, UPF, SMF, etc. The communication between the gateway and the core network can be performed based on the NG-C / U interface or the 6G-C / U interface. The functions of the base station can be performed by a satellite. That is, the base station can be located on a satellite. The base station located on the satellite can be a base station distributed unit (distributed unit, DU), and the base station centralized unit (centralized unit, CU) can be located in NG-RAN or 6G-RAN. The payload can be processed by a base station located on the satellite. Base stations located on different satellites can be connected to the same core network. A satellite can have one or more base stations. In Figure 2b In non-terrestrial networks, it may not be possible to establish ISLs between satellites. Figure 2c In non-terrestrial networks, ISLs between satellites can be established.

[0086] On the other hand, the composition Figure 1a , Figure 1b , Figure 2a , Figure 2b and / or Figure 2c The entities of the non-terrestrial network shown (eg, satellite, base station, UE, communication node, gateway, etc.) may be configured as follows: In the present invention, the entity may be referred to as a communication node.

[0087] Figure 3 is a block diagram illustrating a first exemplary embodiment of communication nodes constituting a non-terrestrial network.

[0088] like Figure 3 As shown, the communication node 300 may include at least one processor 310, a memory 320, and a transceiver 330 connected to a network to perform communication. In addition, the communication node 300 may further include an input interface device 340, an output interface device 350, a storage device 360, etc. The components included in the communication node 300 may be connected through a bus 370 to communicate with each other.

[0089] However, each component included in the communication node 300 may be connected to the processor 310 through a separate interface or a separate bus instead of the common bus 370. For example, the processor 310 may be connected to at least one of the memory 320, the transceiver 330, the input interface device 340, the output interface device 350, and the storage device 360 ​​through a dedicated interface.

[0090] The processor 310 may execute at least one instruction stored in at least one of the memory 320 and the storage device 360. The processor 310 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the exemplary embodiment of the present invention is executed. Each of the memory 320 and the storage device 360 ​​may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 320 may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0091] On the other hand, a communication node that performs communication in a communication network (eg, a non-terrestrial network) may be configured as follows. Figure 4 The communication nodes shown may be Figure 3 A specific exemplary embodiment of a communication node is shown.

[0092] Figure 4 is a block diagram illustrating a first exemplary embodiment of a communication node performing communications.

[0093] like Figure 4 As shown, each of the first communication node 400a and the second communication node 400b can be a base station or a UE. The first communication node 400a can send a signal to the second communication node 400b. The transmission processor 411 included in the first communication node 400a can receive data (e.g., data unit) from the data source 410. The transmission processor 411 can receive control information from the controller 416. The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE) or PHY control information (e.g., DCI, SCI).

[0094] The transmit processor 411 may generate data symbols by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmit processor 411 may generate control symbols by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). In addition, the transmit processor 411 may generate synchronization / reference symbols for synchronization signals and / or reference signals.

[0095] The Tx MIMO processor 412 may perform spatial processing operations (e.g., precoding operations) on data symbols, control symbols, and / or synchronization / reference symbols. The output (e.g., symbol stream) of the Tx MIMO processor 412 may be provided to a modulator (MOD) included in the transceiver 413a to the transceiver 413t. The modulator may generate modulation symbols by performing processing operations on the symbol stream, and may generate signals by performing additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations, etc.) on the modulation symbols. The signals generated by the modulators of the transceivers 413a to the transceivers 413t may be transmitted through the antennas 414a to the antennas 414t.

[0096] The signal transmitted by the first communication node 400a may be received at the antenna 464a to the antenna 464r of the second communication node 400b. The signal received at the antenna 464a to the antenna 464r may be provided to a demodulator (DEMOD) included in the transceiver 463a to the transceiver 463r. The demodulator (DEMOD) may obtain samples by performing processing operations (e.g., filtering operations, amplification operations, down-conversion operations, digital conversion operations, etc.) on the signal. The demodulator may perform additional processing operations on the samples to obtain symbols. The MIMO detector 462 may perform MIMO detection operations on the symbols. The receiving processor 461 may perform processing operations (e.g., deinterleaving operations, decoding operations, etc.) on the symbols. The output of the receiving processor 461 may be provided to the data sink. 460 and controller 466. For example, data may be provided to data sink 460, and control information may be provided to controller 466.

[0097] On the other hand, the second communication node 400b can send a signal to the first communication node 400a. The transmission processor 468 included in the second communication node 400b can receive data (e.g., data unit) from the data source 467, and perform processing operations on the data to generate data symbols. The transmission processor 468 can receive control information from the controller 466, and perform processing operations on the control information to generate control symbols. In addition, the transmission processor 468 can generate reference symbols by performing processing operations on reference signals.

[0098] The Tx MIMO processor 469 may perform spatial processing operations (e.g., precoding operations) on data symbols, control symbols, and / or reference symbols. The output (e.g., symbol stream) of the Tx MIMO processor 469 may be provided to a modulator (MOD) included in the transceiver 463a to the transceiver 463t. The modulator may generate modulation symbols by performing processing operations on the symbol stream, and may generate signals by performing additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations) on the modulation symbols. The signals generated by the modulators of the transceivers 463a to the transceivers 463t may be transmitted via the antennas 464a to the antennas 464t.

[0099] The signal transmitted by the second communication node 400b can be received at the antenna 414a to the antenna 414r of the first communication node 400a. The signal received at the antenna 414a to the antenna 414r can be provided to the demodulator (DEMOD) included in the transceiver 413a to the transceiver 413r. The demodulator can obtain samples by performing processing operations (e.g., filtering operations, amplification operations, down-conversion operations, digital conversion operations) on the signal. The demodulator can perform additional processing operations on the samples to obtain symbols. The MIMO detector 420 can perform MIMO detection operations on the symbols. The receiving processor 419 can perform processing operations (e.g., deinterleaving operations, decoding operations, etc.) on the symbols. The output of the receiving processor 419 can be provided to the data sink 418 and the controller 416. For example, data can be provided to the data sink 418, and control information can be provided to the controller 416.

[0100] Memory 415 and storage 465 may store data, control information and / or program codes. Scheduler 417 may perform scheduling operations for communications. Figure 4 The processors 411, 412, 419, 461, 468, 469 and the controllers 416 and 466 shown may be Figure 3 The processor 310 shown may be used to execute the methods described in the present invention.

[0101] Figure 5a is a block diagram illustrating a first exemplary embodiment of a transmit path, Figure 5b is a block diagram illustrating a first exemplary implementation of a receive path.

[0102] like Figure 5a and Figure 5bAs shown, the transmission path 510 can be implemented in a communication node that transmits a signal, and the receiving path 520 can be implemented in a communication node that receives a signal. The transmission path 510 may include a channel coding and modulation block 511, a serial-to-parallel (S to P) block 512, an N-point inverse fast Fourier transform (inverse fast Fourier transform) block 513, a parallel-to-serial (P to S) block 514, a cyclic prefix (cyclic prefix, CP) adding block 515 and an up-converter (up-converter, UC) 516. The receiving path 520 may include a down-converter (down-converter, DC) 521, a CP deletion block 522, an S to P block 523, an N-point FFT block 524, a P to S block 525 and a channel decoding and demodulation block 526. Here, N can be a natural number.

[0103] In the transmission path 510, the information bits may be input to the channel coding and modulation block 511. The channel coding and modulation block 511 may perform coding operations (e.g., low-density parity check (LDPC) coding operations, polar coding operations, etc.) and modulation operations (e.g., quadrature phase shift keying (OPSK), quadrature amplitude modulation (QAM), etc.) on the information bits. The output of the channel coding and modulation block 511 may be a modulation symbol sequence.

[0104] The S to P block 512 may convert the frequency domain modulation symbols into parallel symbol streams to generate N parallel symbol streams. N may be an IFFT size or an FFT size. The N-point IFFT block 513 may generate a time domain signal by performing an IFFT operation on the N parallel symbol streams. The P to S block 514 may convert the output (e.g., parallel signals) of the N-point IFFT block 513 into a serial signal to generate a serial signal.

[0105] The CP adding block 515 may insert a CP into the signal. The UC 516 may up-convert the frequency of the output of the CP adding block 515 to a radio frequency (RF) frequency. In addition, the output of the CP adding block 515 may be filtered in baseband before up-conversion.

[0106] The signal transmitted from the transmission path 510 may be input to the reception path 520. The operation in the reception path 520 may be an operation opposite to the operation in the transmission path 510. The DC 521 may down-convert the frequency of the received signal to the baseband frequency. The CP removal block 522 may remove the CP from the signal. The output of the CP removal block 522 may be a serial signal. The S to P block 523 may convert the serial signal into a parallel signal. The N-point FFT block 524 may generate N parallel signals by performing an FFT algorithm. The P to S block 525 may convert the parallel signal into a modulation symbol sequence. The channel decoding and demodulation block 526 may perform a demodulation operation on the modulation symbol, and may recover the data by performing a decoding operation on the result of the demodulation operation.

[0107] exist Figure 5a and Figure 5b In the present invention, discrete Fourier transform (DFT) and inverse DFT (IDFT) can be used to replace FFT and IFFT. Figure 5a and Figure 5b Each of the blocks (eg, components) in the embodiment may be implemented by at least one of hardware, software, or firmware. Figure 5a and Figure 5b Some blocks in the can be implemented by software, and other blocks can be implemented by hardware or a combination of hardware and software. Figure 5a and Figure 5b In the , a block can be subdivided into multiple blocks, multiple blocks can be integrated into one block, some blocks can be omitted, and blocks that support other functions can be added.

[0108] On the other hand, the NTN reference scenario may be defined as shown in Table 1 below.

[0109] [Table 1]

[0110] NTN shown in Figure 1 NTN shown in Figure 2 GEO Scenario A Scenario B LEO (Steering Beam) Scenario C1 Scenario D1 LEO (beam that moves with the satellite) Scenario C2 Scene D2

[0111] when Figure 1a and / or Figure 1b When the satellite 110 in the NTN shown is a GEO satellite (e.g., a GEO satellite supporting transparency functionality), this may be referred to as "Scenario A". Figure 2a , Figure 2b and / or Figure 2c When satellite 211 and satellite 212 in the illustrated NTN are GEO satellites (eg, GEOs supporting regeneration functionality), this may be referred to as "scenario B."

[0112] when Figure 1a and / or Figure 1bWhen the satellite 110 in the NTN shown is a LEO satellite with a steerable beam, this may be referred to as "Scenario C1". Figure 1a and / or Figure 1b When the satellite 110 in the NTN shown is a LEO satellite with a beam that moves with the satellite, this may be referred to as "Scenario C2". Figure 2a , Figure 2b and / or Figure 2c When satellite 211 and satellite 212 in the NTN shown are LEO satellites with steerable beams, this may be referred to as "Scenario D1". Figure 2a , Figure 2b and / or Figure 2c When satellite 211 and satellite 212 in the NTN shown are LEO satellites with beams that move with the satellites, this may be referred to as "scenario D2".

[0113] Parameters for the NTN reference scenario defined in Table 1 may be defined as shown in Table 2 below.

[0114] [Table 2]

[0115]

[0116]

[0117] In addition, in the scenario defined in Table 1, the delay constraint may be defined as shown in Table 3 below.

[0118] [Table 3]

[0119]

[0120] Figure 6a is a conceptual diagram showing a first exemplary embodiment of a protocol stack for a user plane in a non-terrestrial network based on a transparent payload, Figure 6b is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack of a control plane in a non-terrestrial network based on a transparent payload.

[0121] like Figure 6a and Figure 6b As shown, user data can be sent and received between the UE and the core network (e.g., UPF), and control data (e.g., control information) can be sent and received between the UE and the core network (e.g., AMF). Each of the user data and the control data can be sent and received via a satellite and / or a gateway. Figure 6a The protocol stack of the user plane shown can be applied identically or similarly to a 6G communication network. Figure 6b The control plane protocol stack shown can be applied identically or similarly to a 6G communication network.

[0122] Figure 7ais a conceptual diagram illustrating a first exemplary embodiment of a protocol stack for a user plane in a non-terrestrial network based on a regenerative payload, Figure 7b is a conceptual diagram illustrating a first exemplary embodiment of a protocol stack for a control plane in a non-terrestrial network based on a regenerative payload.

[0123] like Figure 7a and Figure 7b As shown, each of user data and control data (e.g., control information) can be sent and received through an interface between a UE and a satellite (e.g., a base station). User data can refer to a user protocol data unit (PDU). A protocol stack of a satellite radio interface (SRI) can be used to send and receive user data and / or control data between a satellite and a gateway. User data can be sent and received between a satellite and a core network through a general packet radio service (GPRS) tunneling protocol (GTP)-U tunnel.

[0124] On the other hand, in a non-terrestrial network, the base station may transmit system information (e.g., SIB19) including satellite assistance information for NTN access. The UE may receive the system information (e.g., SIB19) from the base station, identify the satellite assistance information included in the system information, and perform communication (e.g., non-terrestrial communication) based on the satellite assistance information. SIB19 may include the information elements defined in Table 4 below.

[0125] [Table 4]

[0126]

[0127] The NTN-Config defined in Table 4 may include the information elements defined in Table 5 below.

[0128] [Table 5]

[0129]

[0130]

[0131] The EphemerisInfo defined in Table 5 may include the information elements defined in the following Table 6.

[0132] [Table 6]

[0133]

[0134] Hereinafter, a resource management method in a communication system including a non-terrestrial network will be described. Even when describing a method performed by a first communication node among communication nodes (e.g., transmission or reception of a signal), the corresponding second communication node may also perform a method corresponding to the method performed by the first communication node (e.g., reception or transmission of a signal). That is, when describing the operation of a terminal, the corresponding base station (or satellite) may perform an operation corresponding to the operation of the terminal. Conversely, when describing the operation of a base station (or satellite), the corresponding terminal may perform an operation corresponding to the operation of the base station (or satellite).

[0135] Figure 8 is a conceptual diagram illustrating a difference in handover according to a cell type in a non-terrestrial network (NTN).

[0136] like Figure 8 As shown, the communication system may be configured to include a non-terrestrial network (NTN) and / or a terrestrial network (TN). For example, the communication system may include an NTN configured to provide services to a predetermined coverage area, wherein the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be connected to the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Figure 8 When describing the differences in handover according to cell types in NTN, the same references as in FIGS. 1 to 3 may be omitted. Figure 7b Those described are repeated descriptions.

[0137] NTN can support earth-fixed cells (EFC) (or earth-fixed service links). EFC can be formed based on geosynchronous satellites. NTN can support earth-moving cells (EMC) (or earth-moving service links). EMC can be formed based on non-geostationary satellites (i.e., mobile satellites).

[0138] In the case of EMC, handovers may occur continuously depending on the movement of the satellite. That is, in an EMC-based NTN, the frequency of handovers that occur over time may be relatively uniform. On the other hand, in the case of EFC, a large number of handovers may be required simultaneously in a short period of time, rather than handovers occurring continuously. For example, in an EFC-based NTN, when a cell switching occurs, the number of handovers that need to be performed in a short period of time may periodically peak or burst. This phenomenon may be more pronounced as the altitude of the satellite increases.

[0139] Fig. 9 is a sequence diagram illustrating an exemplary implementation of a handover procedure in a terrestrial network (TN).

[0140] like Fig. 9 As shown, the communication system may be configured to include an NTN and / or a TN. For example, the communication system may include a TN configured to provide services to a predetermined coverage area based on one or more ground base stations (e.g., gNBs). Fig. 9 When describing the exemplary implementation of the handover process in the TN, the above-mentioned descriptions with reference to FIGS. 1 to 3 may be omitted. Figure 8 Those described are repeated descriptions.

[0141] In a communication system 900 including a TN, a user equipment (UE) 901 may be connected to a source base station 902. Here, a handover process may be performed in which the UE 901 moves from the source base station 902 to the target base station 903. Such a handover process may be triggered or initiated by at least one node among the UE 901, the source base station 902, and the target base station 903.

[0142] For example, the source base station 902 may trigger or initiate a handover process. The source base station 902 may send a handover request message to the target base station 903 (S910). The target base station 903 may receive the handover request message sent from the source base station 902 (S910). In step S910, the handover request message may be sent and received via an Xn interface, etc. In step S910, the handover request message may be sent based on a measurement report from the UE 901.

[0143] The target base station 903 may perform admission control based on the handover request message (S915). In step S915, the target base station 903 may newly configure radio resources such as a BWP for the UE 901. The BWP configured by the target base station 903 for the UE 901 in step S915 may be the same as or different from the BWP configured or allocated by the source base station 902 for the UE 901.

[0144] The target base station 903 may send a handover acknowledgment (ACK) message to the source base station 902 (S920). The target base station 903 may provide a radio resource control (RRC) configuration. The target base station 903 may provide information about the new BWP configured in step S915 to the source base station 902 through the handover ACK message. The source base station 902 may receive the handover ACK message sent by the target base station 903 (S920).

[0145] The source base station 902 may send a handover command message to the UE 901 based on the handover ACK message sent from the target base station 903 (S930). The UE 901 may receive the handover command message sent from the source base station 902 (S930). The handover command message sent at step S930 may include at least all the information required for the UE 901 to access the cell of the target base station 903. Accordingly, the UE 901 may access the cell of the target base station 903 based on the handover command message without reading the system information of the cell of the target base station 903. For example, the handover command message may include information required for contention-based random access or contention-free random access. The handover command message may include information of the new BWP configured by the target base station 903 in step S915.

[0146] UE 901 may perform handover to target base station 903 based on the handover command message sent from source base station 902 (S935-1). In other words, UE 901 may move the RRC connection to target base station 903 or its cell. Here, the configuration of the new BWP configured in step S915 may be activated. The configuration of the new BWP configured in step S915 may also be activated in target base station 903 (S935-2).

[0147] The UE 901 may transmit a handover completion message to the target base station 903 (S940). The target base station 903 may receive the handover completion message transmitted from the UE 901 (S940). Thus, the handover process may be completed.

[0148] Figures 10a to 10c is a conceptual diagram describing an exemplary implementation of handover in an NTN.

[0149] like Figures 10a to 10c As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Figures 10a to 10c In the exemplary embodiment for describing the handover in the NTN, the above-mentioned exemplary embodiments may be omitted. Fig. 9 Those described are repeated descriptions.

[0150] In NTN, a user or UE can be connected to an NTN gateway based on an NTN satellite or an NTN payload satellite, and can be connected to a ground base station (e.g., gNB) based on an NTN gateway. Handover scenarios for NTN can be classified into intra-satellite handover, inter-satellite handover, and inter-access handover. Intra-satellite handover can occur between cells served by the same satellite. Inter-satellite handover can occur between cells served by different satellites. Inter-access handover can occur between cellular access and satellite access. In the case of a satellite based on a transparent payload (e.g., a satellite supporting transparent functions), intra-gNB handover and / or inter-gNB handover can occur. The configuration described for "gNB" in the present invention can be replaced with a configuration for a "ground base station".

[0151] Fig.10a The handover scenario 1 shown in FIG. 1 may correspond to an exemplary implementation of an inter-satellite / intra-gNB handover. A user or UE within the target service area 1041 may be moved from an existing NTN payload satellite 1031 to a new NTN payload satellite 1032. Here, the existing NTN payload satellite 1031 and the new NTN payload satellite 1032 may be satellites connected to the same ground base station 1011 via the same NTN gateway 1021. The cell movement (or change) according to handover scenario 1 may also be referred to as "cell switching" or "service link switching".

[0152] Fig.10b The handover scenario 2 shown in FIG. 1 may correspond to an exemplary implementation of an intra-satellite / inter-gNB handover. Users or UEs within the target service area 1041 may be served by a new cell of the same NTN payload satellite 1031. The NTN payload satellite 1031 connected to the existing ground base station 1011 through the existing NTN gateway 1021 may be connected to the new ground base station 1012 through the new NTN gateway 1022. In other words, the feeder link of the NTN payload satellite 1031 may be switched from the existing ground base station 1011 to the new ground base station 1012.

[0153] Fig.10c The handover scenario 3 shown in FIG. 104 may correspond to an exemplary implementation of an inter-satellite / inter-gNB handover. A user or UE within the target service area 1041 may be moved from the existing NTN payload satellite 1031 to the new NTN payload satellite 1032. Here, the existing NTN payload satellite 1031 and the new NTN payload satellite 1032 may be satellites connected to different ground base stations 1011 and 1012 through different NTN gateways 1021 and 1022. That is, in handover scenario 3, both the satellite and the ground base station to which the user (or UE) is connected may be switched.

[0154] In a transparent payload based NTN, handover may or may not involve feeder link switching. Fig.10a The transfer scenarios 1 and Fig.10c In the handover case 3 shown in FIG. 1 , a feeder link is pre-established between the ground base station and the satellite, so feeder link switching may not be performed. Fig.10b In the illustrated handover scenario 2, the ground base station connected to the satellite may be changed. That is, handover scenario 2 may be considered to involve a feeder link switch.

[0155] Fig.11a and Fig.11b is a conceptual diagram describing an exemplary embodiment of a feeder link switching method in an NTN.

[0156] like Fig.11a and Fig.11b As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Fig.11a and Fig.11b In the exemplary embodiment of the feeder link switching method in the NTN, the above-mentioned exemplary embodiment may be omitted. Fig.10c Those described are repeated descriptions.

[0157] In NTN, a feeder link may refer to a link between a satellite and an NTN gateway (or ground base station). In a non-GEO satellite-based NTN environment, the connection between the satellite and the NTN gateway may be switched to another NTN gateway depending on the movement of the satellite. This may be referred to as "feeder link switching" or "feeder link conversion".

[0158] The feeder link switching may include a soft feeder link switching, in which the connection between the satellite and multiple NTN gateways may be temporarily maintained during the feeder link switching, and a hard feeder link switching, in which the connection between the satellite and only one NTN gateway may be maintained during the feeder link switching. A radio link interruption may occur during the hard feeder link switching process.

[0159] exist Fig.11aIn the exemplary embodiment of the soft feed link switching shown, the feed link switching can be performed based on a predetermined transition threshold. Here, the satellite can be connected to a gateway (i.e., GW1) in time T1. In the time T1.5 when the soft feed link switching is performed, the connection between the satellite and GW1 and the connection between the satellite and GW2 can be temporarily maintained at the same time. In the time T2 when the soft feed link switching is completed, only the connection between the satellite and GW2 can be maintained.

[0160] exist Fig.11b In the exemplary embodiment of the hard feeder link switching shown, the feeder link switching can be performed based on a predetermined transition threshold. Here, the satellite can be connected to one gateway (i.e., GW1) during time T1. At time T2 when the hard feeder link switching is completed, the satellite and only GW2 can be connected.

[0161] Fig.12 is a conceptual diagram describing the difference between handover in TN and handover in NTN.

[0162] like Fig.12 As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Fig.12 When describing the difference between handover in TN and handover in NTN, the above-mentioned references to FIGS. 1 to 4 may be omitted. Fig.11b Those described are repeated descriptions.

[0163] like Fig.12 As shown in (a), in the handover process in the TN environment, the target base station can newly configure the radio resources such as the BWP of the terminal requested for handover, and the information about the newly configured BWP can be delivered to the terminal through the serving base station. The terminal can use the delivered BWP configuration information to continue the random access channel (RACH) processing and the subsequent connection establishment processing with the target base station.

[0164] like Fig.12As shown in (b), in the NTN, handover may occur due to the movement of the satellite or NTN cell rather than due to the movement of the terminal. Therefore, handover in the NTN environment may be performed differently from handover in the TN environment. For example, when handover occurs due to a new satellite entering the service area of ​​an existing satellite, the new satellite may preferably maintain the same BWP configuration of the terminal configured by the existing satellite. Handover technology that can improve the efficiency of BWP configuration and operation in the NTN environment may be required.

[0165] For example, in an exemplary embodiment of a communication system including an NTN, during the handover process, the target cell may be configured with the same BWP configuration as that configured for the terminal in the existing source cell. Accordingly, the target cell may only signal whether to use the same BWP configuration as before, rather than signaling all information about the BWP configuration. This may minimize signaling overhead. In addition, BWP reconfiguration and BWP switching at the terminal may be minimized.

[0166] Fig.13 is a sequence diagram describing a first exemplary embodiment of a resource management method in a communication system.

[0167] like Fig.13 As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Fig.13 In the first exemplary embodiment of the resource management method in the communication system, the above-mentioned steps may be omitted. Fig.12 Those described are repeated descriptions.

[0168] In a first exemplary embodiment of a resource management method in a communication system, a communication system 1300 including an NTN may support a resource management method according to reference Fig.10a The handover of handover scenario 1 described herein. Handover scenario 1 may correspond to an exemplary implementation of an inter-satellite / intra-gNB handover. Cell movement (or change) according to handover scenario 1 may also be referred to as “cell switching” or “service link switching”.

[0169] In handover scenario 1, UE 1341 may perform handover from an existing satellite (SAT) 1331 (i.e., an existing serving satellite) to a new SAT 1332 (i.e., a target satellite). Here, the existing SAT 1331 and the new SAT 1332 may be connected to the same ground base station 1311 (e.g., a gNB). The existing SAT 1331 and / or the new SAT 1332 may be satellites based on a transparent payload.

[0170] In handover scenario 1, the satellite covering the service area where UE 1341 is located may change due to the movement of the satellite. In this case, the "source cell" may refer to the cell provided by the existing SAT 1331, and the "target cell" may refer to the cell provided by the new SAT 1332. The satellite providing service to UE 1341 may change from the existing SAT 1331 to the new SAT 1332, but the ground base station 1311 may not change. In this case, signaling between the serving ground base station and the target ground base station through the Xn interface may not be required during the handover process. A feeder link between the ground base station 1311 and the satellite (i.e., the existing SAT 1331 and the new SAT 1332) may be established in advance. During the handover process, uplink / downlink transmission may be performed through the feeder link corresponding to the corresponding satellite (i.e., the existing SAT 1331 and the new SAT 1332).

[0171] Specifically, UE 1341 may perform measurement reporting to existing SAT 1331 (ie, source cell) (S1350). Existing SAT 1331 may receive the measurement report from UE 1341 (S1350). Existing SAT 1331 may send the measurement report from UE 1341 to ground base station 1311 (S1350).

[0172] The ground base station 1311 may decide whether to perform a handover based on the measurement report (S1360). For example, the ground base station 1311 may determine whether a handover condition is met based on information such as signal strength, location, and timer identified based on the measurement report. If the handover condition is met, the ground base station 1311 may decide to handover (S1360). In step S1360, the ground base station 1311 may determine that the UE 1341 will be handed over from the existing SAT 1331 to the new SAT 1332.

[0173] The ground base station 1311 may perform admission control based on the handover decision (S1370). In step S1370, the ground base station 1311 may configure radio resources such as BWP for the UE 1341. In other words, in step S1370, the ground base station 1311 may configure a first BWP configuration for the UE 1341. The BWP configured according to the first BWP may be the same as or at least partially overlap with the BWP used to serve the UE 1341 in the existing SAT 1331. That is, the BWP configured by the ground base station 1311 for the UE 1341 in step S1370 may be the same as or at least partially overlap with the BWP configured or allocated for the UE 1341 in the source cell of the existing SAT 1331. Here, "the BWP configured or allocated for the UE 1341 in the source cell of the existing SAT 1331" may mean n activated BWPs configured or allocated for serving the UE 1341 in the source cell of the existing SAT 1331. Here, n may be a natural number.

[0174] The ground base station 1311 may send a handover command message to the existing SAT 1331 (S1380). The handover command message sent by the ground base station 1311 may include information about the first BWP configuration configured at step S1370. The information about the first BWP configuration included in the handover command message may include information about whether the BWP configured according to the first BWP is the same as the BWP used to serve the UE 1341 in the source cell of the existing SAT 1331. Alternatively, the information about the first BWP configuration included in the handover command message may indicate at least some specific details about the first BWP configuration determined at step S1370.

[0175] The existing SAT 1331 may receive the handover command message transmitted from the ground base station 1311 (S1380). The existing SAT 1331 may transmit the handover command message transmitted from the ground base station 1311 to the UE 1341 (S1380). Alternatively, the existing SAT 1331 may generate a new handover command message based on the handover command message transmitted from the ground base station 1311, and transmit it to the UE 1341 (S1380). The UE 1341 may receive the handover command message from the existing SAT 1331.

[0176] UE 1341 may receive a handover command message sent from existing SAT 1331 (S1380). The handover command message sent at step S1380 may include at least all information required for UE 1341 to access a cell of new SAT 1332. Accordingly, UE 1341 may access a cell of new SAT 1332 based on the handover command message without reading system information.

[0177] UE 1341 may perform handover to new SAT 1332 based on the handover command message transmitted from existing SAT 1331 (S1385-1). In step S1385-1, UE 1341 may perform RACH processing for new SAT 1332. UE 1341 may perform a connection establishment procedure for new SAT 1332. The operation of step S1385-1 may be performed based on information about the first BWP configuration included in the handover command message.

[0178] Thereafter, a handover completion process may be performed (S1390). For example, UE 1341 may send a handover completion message to new SAT 1332. New SAT 1332 may receive the handover completion message sent from UE 1341 (S1390). New SAT 1332 may send the handover completion message sent from UE 1341 to ground base station 1311. Accordingly, the handover process may be completed.

[0179] On the other hand, the UE 1341 may perform an operation for BWP activation based on the information about the first BWP configuration at step S1385-1, and may also perform and complete handover to the new SAT 1332 at step S1390.

[0180] In step S1370, the first BWP configuration may be configured as follows:

[0181] 1-1. The ground base station 1311 may identically configure only one of the activated BWPs used in the cell of the existing SAT 1331 (i.e., the source cell) in the cell of the new SAT 1332 (i.e., the target cell). Information thereof may be sent to the UE 1341. In this case, after the handover is completed in step S1390, the remaining BWPs may be configured through a reconfiguration process in the target cell.

[0182] 1-2. The ground base station 1311 may try to configure only one of the activated BWPs used in the cell of the existing SAT 1331 (ie, the source cell) identically in the cell of the new SAT 1332 (ie, the target cell), but may fail. In this case, BWP reconfiguration may be performed, and information about the BWP reconfiguration may be sent to the UE 1341.

[0183] 2-1. The ground base station 1311 may identically configure or attempt to configure k BWPs among the activated BWPs used in the cell (i.e., source cell) of the existing SAT 1331 in the cell (i.e., target cell) of the new SAT 1332. Information thereof may be sent to the UE 1341. In this case, after the handover is completed in step S1390, the remaining BWPs (i.e., the remaining BWPs except for the k BWPs) may be configured through a reconfiguration process in the target cell.

[0184] 2-2. k BWPs may be selected in the order of their BWP indices.

[0185] 2-3. Information about the BWPs of the same configuration and the BWPs of non-same configuration among the k BWPs may be sent to the UE 1341. For example, when k=4, information about the indexes of the BWPs of the same configuration among BWP#1 to BWP#4 may be sent to the UE 1341. If BWP#1, BWP#3, and BWP#4 are configured identically, their information (e.g., bitmap "1011") may be sent to the UE 1341. In this case, after the handover is completed in step S1390, the BWPs of non-same configuration (e.g., BWP#2) may be configured through a reconfiguration process in the target cell.

[0186] 2-4. If the ground base station 1311 does not configure even one of the activated BWPs used in the cell of the existing SAT 1331 (ie, the source cell) the same, BWP reconfiguration may be performed and information thereof may be transmitted to the UE 1341 .

[0187] In step S1370, among n activated BWPs for UE 1341 in the cell serving the existing SAT 1331, k activated BWPs may be identically configured for UE 1341 in the cell serving the new SAT 1332. Here, n may be a natural number, and k may be a natural number less than or equal to n. In other words, configuration of nk activated BWPs among n activated BWPs for UE 1341 in the cell serving the existing SAT 1331 may not be performed in step S1370. In this case, configuration of (nk) activated BWPs not configured in step S1370 may be performed by a reconfiguration process in the target cell. The ground base station 1311 may send first configuration information including instructions related thereto to the UE 1341, the existing SAT 1331, the new SAT 1332, and the like.

[0188] The first configuration information may indicate Fig.13, to perform the handover process for UE 1341. If some activated BWPs configured in the existing source cell for serving UE 1341 are configured to serve UE 1341 in the target cell when UE 1341 performs a specific (or non-specific) handover process, the first configuration information may indicate that the configuration of the remaining activated BWPs is performed through a BWP reconfiguration process in the target cell.

[0189] The signaling operation of the first configuration information may be performed before, during, or after the handover process. Fig.13 In the exemplary embodiment shown, the signaling operation of the first configuration information may be performed when UE 1341 accesses the cell of the existing SAT 1331. Alternatively, the signaling operation of the first configuration information may be performed after the handover process of UE 1341 to the cell of the new SAT 1332 is triggered. Alternatively, the signaling operation of the first configuration information may be performed after UE 1341 completes the handover to the cell of the new SAT 1332.

[0190] The first configuration information may be determined by the ground base station 1311. Alternatively, the first configuration information may be determined by an entity (e.g., a core network, etc.) that is an upper entity of the ground base station 1311. A signaling operation of the first configuration information may be performed between at least some nodes of the ground base station 1311, the UE 1341, the existing SAT 1331, and the new SAT 1332.

[0191] Fig.14 is a sequence diagram describing a second exemplary embodiment of a resource management method in a communication system.

[0192] like Fig.14 As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Fig.14 In the second exemplary embodiment of the resource management method in the communication system, the above-mentioned steps may be omitted. Fig.13 Those described are repeated descriptions.

[0193] In a second exemplary embodiment of a resource management method in a communication system, a communication system 1400 including an NTN may support a resource management method according to reference Fig.10b Described handover for handover scenario 2. Handover scenario 2 may correspond to an exemplary implementation of intra-satellite / inter-gNB handover.

[0194] In handover case 2, UE 1441 may perform handover from an existing cell 1431 (i.e., a serving cell) formed by SAT 1430 to a new cell 1432 (i.e., a target cell) formed by SAT 1430. Here, the existing cell 1431 and the new cell 1432 may be connected to different ground base stations 1411 and 1412 (e.g., gNBs). The existing cell 1431 and / or the new cell 1432 may be formed by a satellite based on a transparent payload.

[0195] In handover scenario 2, the satellite cell covering the service area where UE 1441 is located may change. Specifically, the satellite (i.e., SAT 1430) covering the service area where UE 1441 is located is the same, but as the ground base station is changed from the existing ground base station 1411 to the new ground base station 1412, the satellite cell may also be changed from the existing cell 1431 (i.e., the source cell) to the new cell 1432 (i.e., the target cell).

[0196] Specifically, UE 1441 may perform measurement reporting to existing cell 1431 (ie, source cell) (S1450). Existing cell 1431 may receive measurement reporting from UE 1441 (S1450). Existing cell 1431 may send measurement reporting from UE 1441 to existing ground base station 1411 (S1450).

[0197] The existing ground base station 1411 may decide whether to perform a handover based on the measurement report (S1460). For example, the existing ground base station 1411 may determine whether a handover condition is met based on information such as signal strength, location, and timer identified based on the measurement report. If the handover condition is met, the existing ground base station 1411 may decide to handover (S1460). In step S1460, the existing ground base station 1411 may determine that the UE 1441 will be handed over from the existing cell 1431 to the new cell 1432.

[0198] The existing ground base station 1411 may send a handover request message to the new ground base station 1412 based on the handover decision (S1465). Here, the handover request may include information about the BWP for serving the UE 1441 in the existing cell 1431. The new ground base station 1412 may receive the handover request message sent from the existing ground base station 1411 (S1465).

[0199] The new ground base station 1412 may perform admission control based on the handover request message sent from the existing ground base station 1411 (S1470). In step S1470, the new ground base station 1412 may configure radio resources such as a BWP for the UE 1441. In other words, in step S1470, the new ground base station 1412 may configure a first BWP configuration for the UE 1441. The BWP configured according to the first BWP may be the same as or at least partially overlap with the BWP used to serve the UE 1441 in the existing cell 1431. That is, the BWP configured by the new ground base station 1412 for the UE 1441 in step S1470 may be the same as or at least partially overlap with the BWP configured or allocated for the UE 1441 in the existing cell 1431. Here, "the BWP configured or allocated for the UE 1441 in the existing cell 1431" may refer to n activated BWPs configured or allocated for serving the UE 1441 in the existing cell 1431. Here, n may be a natural number.

[0200] The new ground base station 1412 may send a handover request ACK message as a response to the handover request to the existing ground base station 1411 (S1475). The handover request ACK message sent by the new ground base station 1412 may include information about the first BWP configuration configured at step S1470. The information about the first BWP configuration included in the handover request ACK message may include information about whether the BWP configured according to the first BWP is the same as the BWP used to serve the UE 1441 in the existing cell 1431. Alternatively, the information about the first BWP configuration included in the handover command message may indicate at least some specific details about the first BWP configuration determined at step S1470.

[0201] The existing ground base station 1411 may send a handover command message to the existing cell 1431 based on the received handover request ACK message (S1480). The handover command message may include information about the first BWP configuration configured in step S1470. The information about the first BWP configuration included in the handover command message may include information about whether the BWP configured according to the first BWP is the same as the BWP used to serve the UE 1441 in the existing cell 1431. Alternatively, the information about the first BWP configuration included in the handover command message may indicate at least some specific details about the first BWP configuration determined in step S1470.

[0202] The existing cell 1431 may receive the handover command message transmitted from the existing ground base station 1411 (S1480). The existing cell 1431 may transmit the handover command message transmitted from the existing ground base station 1411 to the UE 1441 (S1480). Alternatively, the existing cell 1431 may generate a new handover command message based on the handover command message transmitted from the existing ground base station 1411, and transmit it to the UE 1441 (S1480). The UE 1441 may receive the handover command message from the existing cell 1431.

[0203] UE 1441 may receive a handover command message sent from existing cell 1431 (S1480). The handover command message sent at step S1480 may include at least all information required for UE 1441 to access new cell 1432. Accordingly, UE 1441 may access new cell 1432 based on the handover command message without reading system information.

[0204] UE 1441 may perform handover to new cell 1432 based on the handover command message transmitted from existing cell 1431 (S1485-1). In step S1485-1, UE 1441 may perform RACH processing for new cell 1432. UE 1441 may perform a connection establishment procedure for new cell 1432. The operation of step S1485-1 may be performed based on information about the first BWP configuration included in the handover command message.

[0205] Thereafter, a handover completion process may be performed (S1490). For example, UE 1441 may send a handover completion message to new cell 1432. New cell 1432 may receive the handover completion message sent from UE 1441 (S1490). New SAT 1432 may send the handover completion message sent from UE 1441 to new ground base station 1412. Accordingly, the handover process may be completed.

[0206] On the other hand, the UE 1441 may perform an operation for BWP activation based on the information about the first BWP configuration at step S1485-1, and may also perform and complete handover to the new cell 1432 at step S1490.

[0207] In step S1470, the first BWP configuration may be configured as follows:

[0208] 1-1. The new ground base station 1412 may identically configure only one of the activated BWPs used in the existing cell 1431 (i.e., the source cell) in the new cell 1432 (i.e., the target cell). Information thereof may be sent to the UE 1441. In this case, after the handover is completed in step S1490, the remaining BWPs may be configured through a reconfiguration process in the target cell.

[0209] 1-2. The new ground base station 1412 may attempt to identically configure only one of the activated BWPs used in the existing cell 1431 (ie, the source cell) in the new cell 1432 (ie, the target cell), but may fail. In this case, BWP reconfiguration may be performed, and information about the BWP reconfiguration may be sent to the UE 1441.

[0210] 2-1. The new ground base station 1412 may configure or attempt to configure k BWPs among the activated BWPs used in the existing cell 1431 (i.e., the source cell) identically in the new cell 1432 (i.e., the target cell). Information thereof may be sent to the UE 1441. In this case, after the handover is completed in step S1490, the remaining BWPs (i.e., the remaining BWPs except for the k BWPs) may be configured through a reconfiguration process in the target cell.

[0211] 2-2. k BWPs may be selected in the order of their BWP indices.

[0212] 2-3. Information about the BWPs of the same configuration and the BWPs of non-same configuration among the k BWPs may be sent to the UE 1441. For example, when k=4, information about the indexes of the BWPs of the same configuration among BWP#1 to BWP#4 may be sent to the UE 1441. For example, if BWP#1, BWP#3, and BWP#4 are configured identically, their information (e.g., bitmap "1011") may be sent to the UE 1441. In this case, after the handover is completed in step S1490, the BWPs of non-same configuration (e.g., BWP#2) may be configured through a reconfiguration process in the target cell.

[0213] 2-4. If the new ground base station 1412 does not configure even one of the activated BWPs used in the existing cell 1431 (ie, the source cell) identically, BWP reconfiguration may be performed and information thereof may be transmitted to the UE 1441 .

[0214] In step S1470, among the n activated BWPs for serving the UE 1441 in the existing cell 1431, k activated BWPs may be identically configured for serving the UE 1441 in the new cell 1432. Here, n may be a natural number, and k may be a natural number less than or equal to n. In other words, configuration of (nk) activated BWPs among the n activated BWPs for serving the UE 1441 in the existing cell 1431 may not be performed in step S1470. In this case, configuration of the (nk) activated BWPs not configured in step S1470 may be performed by a reconfiguration process in the target cell. The existing ground base station 1411 or the new ground base station 1412 may send first configuration information including instructions related thereto to the UE 1441, the existing cell 1431, the new cell 1432, etc.

[0215] The first configuration information may indicate Fig.14 , to perform the handover process for UE 1441. If some activated BWPs configured in the existing source cell for serving UE 1441 are configured to serve UE 1441 in the target cell when UE 1441 performs a specific (or non-specific) handover process, the first configuration information may indicate that the configuration of the remaining activated BWPs is performed through a BWP reconfiguration process in the target cell.

[0216] The signaling operation of the first configuration information may be performed before, during, or after the handover process. Fig.14 In the exemplary embodiment shown, the signaling operation of the first configuration information may be performed when UE 1441 accesses the existing cell 1431. Alternatively, the signaling operation of the first configuration information may be performed after the handover process of UE 1441 to the new cell 1432 is triggered. Alternatively, the signaling operation of the first configuration information may be performed after UE 1441 completes the handover to the new cell 1432.

[0217] The first configuration information may be determined by the existing ground base station 1411 or the new ground base station 1412. Alternatively, the first configuration information may be determined by an entity (such as a core network, etc.) that is an upper entity of the existing ground base station 1411 and / or the new ground base station 1412. A signaling operation of the first configuration information may be performed between at least some nodes of the existing ground base station 1411, the new ground base station 1412, the UE 1441, the existing cell 1431, and the new cell 1432.

[0218] Fig.15 is a sequence diagram describing a third exemplary embodiment of a resource management method in a communication system.

[0219] like Fig.15As shown, the communication system may be configured to include NTN and / or TN. For example, the communication system may include NTN, and the NTN is configured to provide services to a predetermined coverage area, and the predetermined coverage area includes one or more satellites and one or more gateways. Here, the NTN may be used in conjunction with the reference Figures 1a to 7b At least one of the exemplary embodiments of the NTN described herein is the same or similar. Fig.15 In the third exemplary embodiment of the resource management method in the communication system, the above-mentioned reference figures 1 to 4 may be omitted. Fig.14 Those described are repeated descriptions.

[0220] In a third exemplary embodiment of a resource management method in a communication system, a communication system 1500 including an NTN may support a resource management method according to reference Fig.10c The handover of handover scenario 3 described herein. Handover scenario 3 may correspond to an exemplary implementation of an inter-access handover. Handover scenario 3 may correspond to an exemplary implementation of an inter-satellite / inter-gNB handover.

[0221] In handover case 3, UE 1541 may perform handover from a cell formed by an existing SAT 1531 (i.e., a serving cell) to a cell formed by a new SAT 1532 (i.e., a target cell). Here, the existing SAT 1531 and the new SAT 1532 may be connected to different ground base stations 1511 and 1512 (e.g., gNBs). The existing SAT 1531 and / or the new SAT 1532 may be satellite-based with a transparent payload.

[0222] In handover scenario 3, the satellite cell covering the service area where UE 1541 is located may change. Specifically, the satellite (i.e., SAT 1530) covering the service area where UE 1541 is located is the same, but as the ground base station is changed from the existing ground base station 1511 to the new ground base station 1512, the satellite cell may also be changed from the cell of the existing SAT 1531 (i.e., the source cell) to the cell of the new SAT 1532 (i.e., the target cell).

[0223] Specifically, UE 1541 may perform measurement reporting to existing SAT 1531 (ie, source cell) (S1550). Existing SAT 1531 may receive the measurement report from UE 1541 (S1550). Existing SAT 1531 may send the measurement report from UE 1441 to existing ground base station 1411 (S1550).

[0224] The existing ground base station 1511 may decide whether to perform a handover based on the measurement report (S1560). For example, the existing ground base station 1511 may determine whether a handover condition is met based on information such as signal strength, location, and timer identified based on the measurement report. If the handover condition is met, the existing ground base station 1511 may decide to handover (S1560). In step S1560, the existing ground base station 1511 may determine that the UE 1541 will be handed over from the existing SAT 1531 to the new SAT 1532.

[0225] The existing ground base station 1511 may transmit a handover request message to the new ground base station 1512 based on the handover decision (S1565). Here, the handover request may include information about the BWP for serving the UE 1541 in the existing SAT 1531. The new ground base station 1512 may receive the handover request message transmitted from the existing ground base station 1511 (S1565).

[0226] The new ground base station 1512 may perform admission control based on the handover request message sent from the existing ground base station 1511 (S1570). In step S1570, the new ground base station 1512 may configure radio resources such as a BWP for the UE 1541. In other words, in step S1570, the new ground base station 1512 may configure a first BWP configuration for the UE 1541. The BWP configured according to the first BWP may be the same as or at least partially overlap with the BWP used to serve the UE 1541 in the existing SAT 1531. That is, the BWP configured by the new ground base station 1512 for the UE 1541 in step S1570 may be the same as or at least partially overlap with the BWP configured or allocated for the UE 1541 in the existing SAT 1531. Here, "the BWP configured or allocated for the UE 1541 in the existing SAT 1531" may refer to n activated BWPs configured or allocated for serving the UE 1541 in the existing SAT 1531. Here, n may be a natural number.

[0227] The new ground base station 1512 may send a handover request ACK message as a response to the handover request to the existing ground base station 1511 (S1575). The handover request ACK message sent by the new ground base station 1512 may include information about the first BWP configuration configured in step S1570. The information about the first BWP configuration included in the handover request ACK message may include information about whether the BWP configured according to the first BWP is the same as the BWP used to serve the UE 1541 in the existing SAT 1531. Alternatively, the information about the first BWP configuration included in the handover command message may indicate at least some specific details about the first BWP configuration determined in step S1570.

[0228] The existing ground base station 1511 may send a handover command message to the existing SAT 1531 based on the received handover request ACK message (S1580). The handover command message may include information about the first BWP configuration configured at step S1570. The information about the first BWP configuration included in the handover command message may include information about whether the BWP configured according to the first BWP is the same as the BWP used to serve the UE 1541 in the existing SAT 1531. Alternatively, the information about the first BWP configuration included in the handover command message may indicate at least some specific details about the first BWP configuration determined at step S1570.

[0229] The existing SAT 1531 may receive the handover command message transmitted from the existing ground base station 1511 (S1580). The existing SAT 1531 may transmit the handover command message transmitted from the existing ground base station 1511 to the UE 1541 (S1580). Alternatively, the existing SAT 1531 may generate a new handover command message based on the handover command message transmitted from the existing ground base station 1511, and transmit it to the UE 1541 (S1580). The UE 1541 may receive the handover command message from the existing SAT 1531.

[0230] UE 1541 may receive a handover command message transmitted from the existing SAT 1531 (S1580). The handover command message transmitted at step S1580 may include at least all information required for UE 1541 to access the cell of the new SAT 1532. Accordingly, UE 1541 may access the cell of the new SAT 1532 based on the handover command message without reading system information.

[0231] UE 1541 may perform handover to new SAT 1532 based on the handover command message transmitted from existing SAT 1531 (S1585-1). In step S1585-1, UE 1541 may perform RACH processing for new SAT 1532. UE 1541 may perform a connection establishment procedure for new SAT 1532. The operation of step S1585-1 may be performed based on information about the first BWP configuration included in the handover command message.

[0232] Thereafter, a handover completion process may be performed (S1590). For example, UE 1541 may send a handover completion message to new SAT 1532. New SAT 1532 may receive the handover completion message sent from UE 1541 (S1590). New SAT 1532 may send the handover completion message sent from UE 1541 to new ground base station 1512. Accordingly, the handover process may be completed.

[0233] On the other hand, the UE 1541 may perform an operation for BWP activation based on the information about the first BWP configuration at step S1585-1, and may also perform and complete handover to the new SAT 1532 at step S1590.

[0234] In step S1570, the first BWP configuration may be configured as follows:

[0235] 1-1. The new ground base station 1512 may identically configure only one of the activated BWPs used in the cell (i.e., source cell) of the existing SAT 1531 in the cell (i.e., target cell) of the new SAT 1532. Information thereof may be sent to the UE 1541. In this case, after the handover is completed at step S1590, the remaining BWPs may be configured through a reconfiguration process in the target cell.

[0236] 1-2. The new ground base station 152 may try to configure only one of the activated BWPs used in the cell (i.e., source cell) of the existing SAT 1531 identically in the cell (i.e., target cell) of the new SAT 1532, but may fail. In this case, BWP reconfiguration may be performed, and information about the BWP reconfiguration may be sent to the UE 1541.

[0237] 2-1. The new ground base station 1512 may identically configure or attempt to configure k BWPs among the activated BWPs used in the cell (i.e., source cell) of the existing SAT 1531 in the cell (i.e., target cell) of the new SAT 1532. Information thereof may be sent to the UE 1541. In this case, after the handover is completed in step S1590, the remaining BWPs (i.e., the remaining BWPs except for the k BWPs) may be configured through a reconfiguration process in the target cell.

[0238] 2-2. k BWPs may be selected in the order of their BWP indices.

[0239] 2-3. Information about the BWPs of the same configuration and the BWPs of non-same configuration among the k BWPs may be transmitted to the UE 1541. For example, when k=4, information about the indexes of the BWPs of the same configuration among BWP#1 to BWP#4 may be transmitted to the UE 1541. For example, if BWP#1, BWP#3, and BWP#4 are configured identically, their information (e.g., bitmap "1011") may be transmitted to the UE 1541. Here, in this case, after the handover is completed in step S1590, the BWPs of non-same configuration (e.g., BWP#2) may be configured through a reconfiguration process in the target cell.

[0240] 2-4. If the new ground base station 1512 does not configure even one of the activated BWPs used in the cell of the existing SAT 1531 (ie, the source cell) identically, BWP reconfiguration may be performed and information thereof may be sent to the UE 1541 .

[0241] In step S1570, among n activated BWPs for UE 1541 in the cell serving the existing SAT 1531, k activated BWPs may be identically configured for UE 1541 in the cell serving the new SAT 1532. Here, n may be a natural number, and k may be a natural number less than or equal to n. In other words, configuration of (nk) activated BWPs among n activated BWPs for UE 1541 in the cell serving the existing SAT 1531 may not be performed in step S1570. In this case, configuration of (nk) activated BWPs not configured in step S1570 may be performed by a reconfiguration process in the target cell. The existing ground base station 1511 or the new ground base station 1512 may send first configuration information including instructions related thereto to the UE 1541, the existing SAT 1531, the new SAT 1532, etc.

[0242] The first configuration information may indicate Fig.15 , to perform the handover process for UE 1541. If some activated BWPs configured in the existing source cell for serving UE 1541 are configured to serve UE 1541 in the target cell when UE 1541 performs a specific (or non-specific) handover process, the first configuration information may indicate that the configuration of the remaining activated BWPs is performed through a BWP reconfiguration process in the target cell.

[0243] The signaling operation of the first configuration information may be performed before, during, or after the handover process. Fig.15 In the exemplary embodiment shown, the signaling operation of the first configuration information may be performed when UE 1541 accesses the existing SAT 1531. Alternatively, the signaling operation of the first configuration information may be performed after the handover process of UE 1541 to the cell of the new SAT 1532 is triggered. Alternatively, the signaling operation of the first configuration information may be performed after UE 1541 completes the handover to the cell of the new SAT 1532.

[0244] The first configuration information may be determined by the existing ground base station 1511 or the new ground base station 1512. Alternatively, the first configuration information may be determined by an entity (such as a core network, etc.) that is an upper entity of the existing ground base station 1511 and / or the new ground base station 1512. A signaling operation of the first configuration information may be performed between at least some nodes of the existing ground base station 1511, the new ground base station 1512, the UE 1541, the existing SAT 1531, and the new SAT 1532.

[0245] According to an exemplary embodiment of a resource management method and apparatus in a communication system including an NTN, a terminal connected to the NTN can move from a first satellite cell to a second satellite cell. Here, when the terminal moves from the first satellite cell to the second satellite cell, at least a portion of the BWP configured for the terminal of the first satellite cell can be configured identically in the second satellite cell. Since a BWP partially overlapping with a previously used BWP is configured during the cell mobility process of the terminal, the overhead of configuring the BWP and the signaling process for the BWP information can be significantly reduced. Accordingly, the efficiency of the cell mobility process of the terminal can be improved.

[0246] The operation of the method according to the exemplary embodiment of the present invention can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include a recording device of all types having data that can be read by a computer system. In addition, the computer-readable recording medium can store and execute programs or codes, which can be distributed in a computer system connected via a network and read by a computer in a distributed manner.

[0247] Computer readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM or flash memory. Program instructions may include not only machine language codes created by a compiler, but also high-level language codes that can be executed by a computer using an interpreter.

[0248] Although some aspects of the present invention have been described in the context of a device, these aspects may indicate the corresponding description according to the method, and a block or device may correspond to the step of the method or the feature of the step. Similarly, the aspects described in the context of the method may be represented as the feature of a corresponding block or project or a corresponding device. Some or all steps of the method may be performed by (or using) a hardware device such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, one or more of the most important steps of the method may be performed by such a device.

[0249] In some exemplary embodiments, a programmable logic device such as a field programmable gate array can be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, the field programmable gate array can be operated with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by a specific hardware device.

[0250] The description of the present invention is merely exemplary in nature, and therefore variant forms that do not deviate from the essence of the present invention are intended to be within the scope of the present invention. Such variant forms should not be considered as departing from the spirit and scope of the present invention. Therefore, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope defined by the appended claims.

Claims

1. A method for operating a first ground base station, comprising: receiving a first measurement report reported by a first terminal from a first satellite, the first satellite forming a first satellite cell connected to the first terminal; Based on the first measurement report, determining that the first terminal is to be connected to a second satellite cell, where the second satellite cell is formed by a second satellite connected to the first ground base station; identifying n bandwidth parts (BWPs) configured for a first terminal in a first satellite cell; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve a first terminal in a second satellite cell; as well as sending first configuration information to the first satellite, wherein the first configuration information includes first BWP configuration information generated based on a result of the attempt and information indicating that the first terminal is connected to the second satellite cell, Wherein, n is a natural number.

2. The operating method according to claim 1, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; and In response to the first BWP being successfully configured to serve the first terminal, first BWP configuration information is generated, the first BWP configuration information including information indicating that a first BWP among the n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

3. The operating method according to claim 2, further comprising: Second configuration information is sent to the first terminal, where the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

4. The operating method according to claim 1, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; In response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and First BWP configuration information indicating a result of the BWP reconfiguration is generated.

5. The operating method according to claim 1, wherein: The first BWP group includes m BWPs and attempts to include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; and In response to k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, Wherein, m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

6. The operating method according to claim 5, wherein: The m BWPs are first to m-th BWPs selected from among the n BWPs based on BWP indices, and the first BWP configuration information includes corresponding indices of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

7. The operating method according to claim 5, further comprising: Third configuration information is sent to the first terminal, where the third configuration information instructs the first terminal to perform a BWP reconfiguration process with the second satellite cell for nk BWPs except k BWPs among the n BWPs.

8. A method for operating a first ground base station, comprising: receiving a handover request of a first terminal from a second ground base station connected to a first satellite, the first terminal being connected to a first satellite cell formed by a first satellite connected to the first ground base station; Based on the handover request, accepting a handover of the first terminal to a second satellite cell formed by the first satellite; Based on the handover request, identifying n bandwidth parts (BWPs) configured for a first terminal in a first satellite cell; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve a first terminal in a second satellite cell; as well as sending a first response to the second ground base station, wherein the first response includes first BWP configuration information generated based on a result of the attempt and information indicating that the handover request of the first terminal is accepted, Wherein, n is a natural number.

9. The operating method according to claim 8, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; and In response to the first BWP being successfully configured to serve the first terminal, first BWP configuration information is generated, the first BWP configuration information including information indicating that a first BWP among the n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

10. The operating method according to claim 9, further comprising: Second configuration information is sent to the first terminal, where the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

11. The operating method according to claim 8, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; In response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and First BWP configuration information indicating a result of the BWP reconfiguration is generated.

12. The operating method according to claim 8, wherein: The first BWP group includes m BWPs and attempts to include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; and In response to k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, Wherein, m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

13. The operating method according to claim 12, wherein: The m BWPs are first to m-th BWPs selected from among the n BWPs based on BWP indices, and the first BWP configuration information includes corresponding indices of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

14. The operating method according to claim 12, further comprising: Third configuration information is sent to the first terminal, where the third configuration information instructs the first terminal to perform a BWP reconfiguration process with the second satellite cell for nk BWPs except k BWPs among the n BWPs.

15. A method for operating a first ground base station, comprising: receiving a handover request of a first terminal from a second ground base station, the first terminal being connected to a first satellite cell, the first satellite cell being formed by a first satellite connected to the second ground base station; Based on the handover request, accepting a handover of the first terminal to a second satellite cell formed by a second satellite, the second satellite being connected to a second ground base station; Based on the handover request, identifying n bandwidth parts (BWPs) configured for a first terminal in a first satellite cell; attempting to configure a first BWP group including at least one BWP among the n BWPs to serve a first terminal in a second satellite cell; as well as sending a first response to the second ground base station, wherein the first response includes first BWP configuration information generated based on a result of the attempt and information indicating that the handover request of the first terminal is accepted, Wherein, n is a natural number.

16. The operating method according to claim 15, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; and In response to the first BWP being successfully configured to serve the first terminal, first BWP configuration information is generated, the first BWP configuration information including information indicating that a first BWP among the n BWPs configured for the first terminal in the first satellite cell is configured to serve the first terminal in the second satellite cell.

17. The operating method according to claim 16, further comprising: Second configuration information is sent to the first terminal, where the second configuration information instructs the first terminal to perform a BWP reconfiguration process with a second satellite cell for n-1 BWPs among the n BWPs except the first BWP.

18. The operating method according to claim 15, wherein: The first BWP group includes a first BWP and attempts to include: attempting to configure the first BWP to serve the first terminal in the second satellite cell; In response to the first BWP not being configured to serve the first terminal, performing BWP reconfiguration; and First BWP configuration information indicating a result of the BWP reconfiguration is generated.

19. The operating method according to claim 15, wherein: The first BWP group includes m BWPs and attempts to include: attempting to configure k BWPs to serve the first terminal in the second satellite cell; and In response to k BWPs being successfully configured to serve the first terminal, generating first BWP configuration information including information about the k BWPs, Wherein, m is a natural number less than or equal to n, and k is a natural number less than or equal to m.

20. The operating method according to claim 19, wherein: The m BWPs are first to m-th BWPs selected from among the n BWPs based on BWP indices, and the first BWP configuration information includes corresponding indices of the first to m-th BWPs and mapping information of the first to m-th BWPs for k BWPs.

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