Apparatus and method for feeder link handover in NTN communication environment

Abstract

A method for feeder link handover performed by a base station in a non-terrestrial network (NTN) communication environment includes: continuously monitoring the Flow Control Transmission Protocol (SCTP) status; when a first feeder link disconnection between a base station on a satellite and a first terrestrial entity is detected based on the SCTP status, broadcasting a first message across the cell where the base station is located to indicate the disconnection of the first feeder link; and, based on the SCTP status, triggering a Transmission Network Layer (TNL) node on the satellite to release TNL resources allocated to the first terrestrial entity and / or configuring a transmission association for a second feeder link between the base station on the satellite and a second terrestrial entity before the first feeder link disconnection.

Description

Technical Field

[0001] This disclosure relates to the field of communication systems, and more specifically, to apparatus and methods for feeder link switching in non-terrestrial network (NTN) communication environments. Background Technology

[0002] The concept of transparent mode satellite access was introduced in 3GPP Releases 17 and 18 to facilitate the integration of satellite components into Evolved Packet System (EPS) and 5G System (5GS) architectures. This approach assumes that the satellite merely acts as a conduit, forwarding signals without processing them. Recently, a 3GPP Release 19 study was approved to explore the impact of regenerated satellite payloads on EPS. These payloads are designed to embed 3GPP radioaccess network (RAN) and / or core network functions directly onto the satellite. This capability introduces several value-added services for users, such as support for reduced user plane and control plane latency. For network operations, these regenerated payloads provide enhanced flexibility in deploying terrestrial or non-terrestrial network (NTN) gateways relative to the space segment.

[0003] Existing transparent payload scenarios and procedures are insufficient to support feeder link handover in regenerated payload scenarios because feeder link handover in regenerated payloads may require changes to the mobility management entity (MME). Furthermore, existing handover procedures have also proven inadequate in regenerated scenarios because the serving cell and eNB continuously cover the area where the user equipment (UE) is located, preventing handover triggering.

[0004] Therefore, current 3GPP procedures or transparent payload satellite EPS integration procedures cannot solve the feeder link switching problem in regenerative payload scenarios. Thus, there is a need for apparatus and methods for feeder link switching in NTN communication environments that can address the problems in existing technologies and other issues. Summary of the Invention

[0005] The purpose of this disclosure is to provide apparatus and methods for feeder link switching in non-terrestrial network (NTN) communication environments, which can solve problems and other issues in the prior art, and / or support feeder link switching for integration of regenerable payload satellites with evolved packet systems (EPS).

[0006] In a first aspect of this disclosure, a method for feeder link handover in an NTN communication environment, performed by a base station, includes: continuously monitoring the state of a stream control transmission protocol (SCTP); when a first feeder link between a base station on a satellite and a first ground-based entity is detected to be disconnected based on the SCTP state, broadcasting a first message across the cell where the base station is located to indicate the disconnection of the first feeder link; and, based on the SCTP state, triggering a transport network layer (TNL) node on the satellite to release TNL resources allocated to the first ground-based entity and / or configuring a transmission association for a second feeder link between the base station on the satellite and a second ground-based entity before the first feeder link is disconnected.

[0007] In a second aspect of this disclosure, a base station configured in an NTN communication environment includes: a monitor for continuously monitoring SCTP status; a transceiver for broadcasting a first message across the cell where the base station is located to indicate the disconnection of the first feeder link when the monitor detects a disconnection of the first feeder link between the base station on the satellite and a first ground-based entity based on the SCTP status; and a trigger for triggering a TNL node on the satellite to release TNL resources allocated to the first ground-based entity and / or configuring a transmission association of a second feeder link between the base station on the satellite and a second ground-based entity before the disconnection of the first feeder link, based on the SCTP status.

[0008] In a third aspect of this disclosure, a base station includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The base station is used to provide the above-described method.

[0009] In a fourth aspect of this disclosure, a method for feeder link handover performed by a terrestrial entity includes: if the terrestrial entity predicts, based on satellite control data, that a feeder link is about to be disconnected, the terrestrial entity directly notifies the user equipment (UE) of the feeder link handover information via signaling.

[0010] In a fifth aspect of this disclosure, a ground-based entity includes a predictor and a notifier. The predictor is used to predict an impending feeder link disconnection based on satellite control data. The notifier is used to directly notify the UE of the feeder link switching information via signaling.

[0011] In a sixth aspect of this disclosure, a ground-based entity includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. This ground-based entity is used to provide the methods described above.

[0012] In a seventh aspect of this disclosure, a non-transitory machine-readable storage medium is provided having instructions stored thereon that, when executed by a computer, cause the computer to perform the methods described above.

[0013] In an eighth aspect of this disclosure, a chip includes a processor for calling and running a computer program stored in a memory to cause a device on which the chip is mounted to perform the methods described above.

[0014] In a ninth aspect of this disclosure, a computer-readable storage medium stores a computer program that causes a computer to perform the above-described method.

[0015] In a tenth aspect of this disclosure, a computer program product includes a computer program that causes a computer to perform the methods described above.

[0016] In the eleventh aspect of this disclosure, a computer program causes a computer to perform the above-described method. Attached Figure Description

[0017] To more clearly illustrate the embodiments or related technologies of this disclosure, the following drawings, which will be described in the embodiments, will be briefly introduced. Obviously, the drawings are only some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without giving any premise.

[0018] Figure 1 This is a schematic diagram of feeder link switching in a non-terrestrial network (NTN) communication environment.

[0019] Figure 2 This is a schematic diagram of feeder link switching with different mobility management entities (MMEs) in an NTN communication environment.

[0020] Figure 3 This is a block diagram of one or more user equipment (UE) and a base station communicating in a communication network system according to embodiments of the present disclosure.

[0021] Figure 4This is a block diagram of a base station according to an embodiment of the present disclosure.

[0022] Figure 5 This is a block diagram of a base station according to an embodiment of the present disclosure.

[0023] Figure 6 This is a flowchart illustrating a method for feeder link switching performed by a base station in an NTN communication environment according to an embodiment of the present disclosure.

[0024] Figure 7 This is a block diagram of a ground-based entity according to an embodiment of the present disclosure.

[0025] Figure 8 This is a block diagram of a ground-based entity according to an embodiment of the present disclosure.

[0026] Figure 9 This is a flowchart illustrating a method for feeder link switching performed by a ground-based entity according to an embodiment of the present disclosure.

[0027] Figure 10 This is a flowchart illustrating a Tracking Area Update (TAU) with feeder link switching according to an embodiment of the present disclosure.

[0028] Figure 11 This is a block diagram of an example computing device according to an embodiment of the present disclosure.

[0029] Figure 12 This is a block diagram of a communication system according to an embodiment of the present disclosure. Detailed Implementation

[0030] The technical problems, structural features, objectives, and effects of the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Specifically, the terminology used in the embodiments of this disclosure is only for describing a particular embodiment and is not intended to limit the disclosure.

[0031] The technical solutions of this disclosure can be applied to various communication systems, such as Global System for Mobile Communication (GSM), Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Advanced Long Term Evolution (LTE-A) systems, New Radio (NR) systems, evolution systems of NR systems, LTE-based access to unlicensed spectrum (LTE-U) systems, NR-based access to unlicensed spectrum (NR-U) systems, Universal Mobile Telecommunication System (UMTS), and Global Interoperability for Microwave. Access (WiMAX) communication systems, wireless local area networks (WLAN), wireless fidelity (Wi-Fi), future 5th generation (5G) systems (also known as new wireless (NR) systems), or other communication systems.

[0032] Optionally, the base station mentioned in this embodiment can provide communication coverage for a specific geographical area and can communicate with user equipment (UE) located within the coverage area. Optionally, the base station can be a base transceiver station (BTS) in a gNB, GSM, or CDMA system, or a Node B (NB) in a WCDMA system, an evolved Node B (eNB or eNodeB) in an LTE system, or a radio controller in a cloud radio access network (CRAN).

[0033] User equipment (UE) can refer to an access terminal, user unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user equipment. An access terminal can be a cellular wireless phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device, other processing devices coupled to a wireless modem, in-vehicle equipment, wearable device, terminal equipment in future 5G networks, and terminal equipment in future evolved public land mobile networks (PLMNs), etc.

[0034] Optionally, the communication system in this embodiment of the present disclosure can be applied to unlicensed spectrum, wherein unlicensed spectrum can also be regarded as shared spectrum; or, the communication system in this embodiment of the present disclosure can also be applied to licensed spectrum, wherein licensed spectrum can also be regarded as non-shared spectrum.

[0035] The concept of transparent mode satellite access was introduced in 3GPP Releases 17 and 18 to facilitate the integration of satellite components into Evolved Packet System (EPS) and 5G System (5GS) architectures. This approach assumes that the satellite merely acts as a conduit, forwarding signals without processing them. Recently, a 3GPP Release 19 study was approved to explore the impact of regenerated satellite payloads on EPS. These payloads are designed to embed 3GPP radioaccess network (RAN) and / or core network functions directly onto the satellite. This capability introduces several value-added services for users, such as support for reduced user plane and control plane latency and the implementation of inter-satellite link (ISL) communication. For network operations, these regenerated payloads provide enhanced flexibility in deploying terrestrial or non-terrestrial network (NTN) gateways relative to the space segment.

[0036] As part of these studies, the focus is on deploying eNBs or gNBs on satellites, particularly for low Earth orbit (LEO) or medium Earth orbit (MEO) configurations. Key aspects under investigation may include: 1. Determining any potential impacts on 5G and EPS due to embedding gNB / eNB units on satellites. This examination involves assessing the integration and compatibility of these RAN nodes within the existing 5G and EPS frameworks. 2. Investigating the impact of mobile RAN nodes in space. This includes understanding how the movement of these nodes affects network coverage and service continuity in a given area, especially in the context of dynamic and constantly changing satellite locations.

[0037] TS 36.300 describes the feeder link handover procedure in detail in Clause 23.21.5, where a link is transferred from a source NTN gateway to a target NTN gateway for a specific NTN payload. This procedure is part of the transport network layer (TNL) and applies to both hard and soft feeder link handovers. It is important to note that this specification assumes the use of transparent payloads and that the eNB is located at the NTN gateway.

[0038] However, in the case of regenerated payloads, the scenario changes, where the eNB is deployed directly on the satellite, causing the S1-AP interface to terminate on the satellite. For example... Figure 1As shown, this configuration faces challenges due to satellite movement, potentially leading to loss of feeder link connectivity with the NTN gateway. In this scenario, when the LEO satellite leaves the coverage area of ​​NTN GW1, the feeder link may need to switch from NTN GW1 to NTN GW2. Notably, this switch does not affect the Uu interface. This contrasts with transparent payload scenarios, where the eNB is typically co-located with the terrestrial NTN GW to facilitate soft feeder link switching and allow for temporary overlap between feeder links. Such overlap is not feasible in regenerative payloads because the onboard eNB must switch between NTN gateways without any overlap cycles.

[0039] In addition, such as Figure 2 As shown, feeder link handover in a regenerated payload may require changes to the mobility management entity (MME), where MME1 is connected to NTN GW1 and MME2 is connected to NTN GW2. Therefore, to the inventors' knowledge, existing scenarios and procedures are insufficient to support feeder link handover in regenerated payload scenarios. Since the serving cell and eNB continuously cover the area where the UE is located, preventing handover triggering, existing handover procedures have also proven inadequate in regenerated scenarios. Therefore, the current 3GPP procedures or transparent payload satellite EPS integration procedures cannot solve the feeder link handover problem in regenerated payload scenarios. As specified in TS 36.412, only one stream control transmission protocol (SCTP) association is established between an MME and eNB pair. Furthermore, the eNB establishes this SCTP association. Therefore, configuring a transmission association for the target NTN GW feeder link before the source NTN-GW feeder link is disconnected is also preferable.

[0040] Figure 3 The illustration shows one or more UEs 10 and a base station (e.g., a next-generation NodeB (gNB) or eNB) 20 communicating in a communication network system 40 (e.g., an NR system) provided according to embodiments of this disclosure in some embodiments. The communication network system 40 includes one or more UEs 10, a base station 20, and at least one terrestrial entity 30. The at least one terrestrial entity may include a first terrestrial entity and a second terrestrial entity. The at least one terrestrial entity may be an NTN GW or an MME. For example, as... Figure 2As shown, the first terrestrial entity may be NTN GW1 or MME1, and the second terrestrial entity may be NTN GW2 or MME2. One or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. At least one terrestrial entity 30 may include a memory 32, a transceiver 33, and a processor 31 coupled to the memory 32 and the transceiver 33. The processors 11, 21, or 31 may be used to implement the functions, procedures, and / or methods proposed in this specification. The layers of the radio interface protocol may be implemented in the processors 11, 21, or 31. The memory 12, 22, or 32 is operatively coupled to the processors 11, 21, or 31 and stores various information to operate the processors 11, 21, or 31. Transceiver 13, 23, or 33 is operatively coupled to processor 11, 21, or 31, and transceiver 13, 23, or 33 transmits and / or receives wireless signals.

[0041] Processors 11, 21, or 31 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices. Memory 12, 22, or 32 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. Transceivers 13, 23, or 33 may include baseband circuitry for processing radio frequency signals. When this embodiment is implemented in software, the techniques described herein can be implemented by modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules may be stored in memory 12, 22, or 32 and executed by processor 11, 21, or 31. Memory 12, 22, or 32 may be implemented within processor 11, 21, or 31 or external to processor 11, 21, or 31; in the latter case, memory 12, 22, or 32 may be communicatively coupled to processor 11, 21, or 31 in various ways known in the art.

[0042] In some embodiments, the processor 21 is configured to continuously monitor the SCTP status; when the processor 21 detects a disconnection of the first feeder link between the base station 20 on the satellite and the first ground-based entity based on the SCTP status, the transceiver 23 broadcasts a first message across the cell where the base station 20 is located to indicate the disconnection of the first feeder link; the processor 21 is configured to, based on the SCTP status, trigger the TNL node on the satellite to release the TNL resources allocated to the first ground-based entity and / or configure the transmission association of the second feeder link between the base station 20 on the satellite and the second ground-based entity before the disconnection of the first feeder link. This can solve problems in the prior art and other issues, and / or support feeder link switching for regenerating payload satellites and EPS integration.

[0043] Figure 4 An example of a base station 400 according to an embodiment of this application is shown. The base station 400 is used to implement some embodiments of this disclosure. Some embodiments of this disclosure can be implemented in the base station 400 using any appropriately configured hardware and / or software. The base station 400 includes: a monitor 401 for continuously monitoring the SCTP status; a transceiver 402 for broadcasting a first message across the cell where the base station 400 is located to indicate the disconnection of the first feeder link when the monitor 401 detects a disconnection of the first feeder link between the base station 400 on the satellite and a first ground-based entity based on the SCTP status; and a trigger 403 for triggering a TNL node on the satellite to release TNL resources allocated to the first ground-based entity and / or configuring a transmission association for a second feeder link between the base station 400 on the satellite and a second ground-based entity before the disconnection of the first feeder link, based on the SCTP status. This can solve problems in the prior art and other issues, and / or support feeder link switching for regenerating payload satellites and EPS integration. For example, as Figure 2 As shown, the first ground-based entity can be NTN GW1 or MME1, and the second ground-based entity can be NTN GW2 or MME2.

[0044] In some embodiments, if a first terrestrial entity predicts an impending disconnection of a first feeder link based on satellite ephemeris data, transceiver 402 receives a notification from the first terrestrial entity indicating the impending disconnection of the first feeder link. Transceiver 402 then broadcasts a second message across the cell where base station 400 is located to indicate the impending disconnection of the first feeder link. Trigger 403 initiates at least one procedure to release TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between base station 400 on the satellite and the second terrestrial entity prior to the impending disconnection of the first feeder link.

[0045] In some embodiments, trigger 403 is further configured to enable feeder link handover to trigger at least one tracking area update (TAU) procedure. In some embodiments, transceiver 402 is further configured to broadcast at least one satellite ephemeris condition-related information, including the expected start time of the feeder link handover. In some embodiments, when the transceiver notifies the UE of an upcoming feeder link handover, the UE initiates at least one TAU procedure triggered by the feeder link handover. In some embodiments, at least one TAU procedure applies to UEs in EPS connection management (ECM)-IDLE state or ECM-CONNECTED state.

[0046] In some embodiments, at least one TAU procedure includes indicating a cell-barred state in the system minimum information. In some embodiments, at least one TAU procedure includes indicating a cell-barred state in the system minimum information. In some embodiments, if a feeder link switch connects base station 400 to the same MME, trigger 403 derives the MME address from at least one radio resource control (RRC) parameter. In some embodiments, if a feeder link switch connects base station 400 to a new MME, the new MME is predefined. In some embodiments, if at least one TAU procedure is caused by a feeder link switch, the MME triggers a release procedure after at least one TAU procedure is completed.

[0047] Figure 5An example of a base station 500 according to an embodiment of the present disclosure is shown. The base station 500 is used to implement some embodiments of the present disclosure. Some embodiments of the present disclosure can be implemented in the base station 500 using any appropriately configured hardware and / or software. The base station 500 may include a memory 501, a transceiver 502, and a processor 503 coupled to the memory 501 and the transceiver 502. The processor 503 may be used to implement the functions, programs, and / or methods described in this specification. Layers of a wireless interface protocol may be implemented in the processor 503. The memory 501 is operatively coupled to the processor 503 and stores various information to operate the processor 503. The transceiver 502 is operatively coupled to the processor 503 and transmits and / or receives wireless signals. The processor 503 may include an ASIC, other chipsets, logic circuitry, and / or data processing devices. The memory 501 may include ROM, RAM, flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver 502 may include baseband circuitry for processing radio frequency signals. When this embodiment is implemented in software, the techniques described herein can be implemented by modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules can be stored in memory 501 and executed by processor 503. Memory 501 can be implemented within processor 503 or external to processor 503; in the latter case, memory 501 can be communicatively coupled to processor 503 in various ways known in the art.

[0048] In some embodiments, the processor 503 is configured to continuously monitor the SCTP status; when the processor 503 detects a disconnection of the first feeder link between the base station 500 on the satellite and the first ground-based entity based on the SCTP status, the transceiver 502 broadcasts a first message across the cell where the base station 500 is located to indicate the disconnection of the first feeder link; the processor 503 is configured to, based on the SCTP status, trigger the TNL node on the satellite to release the TNL resources allocated to the first ground-based entity and / or configure the transmission association of the second feeder link between the base station 500 on the satellite and the second ground-based entity before the disconnection of the first feeder link. This can solve problems in the prior art and other issues, and / or support feeder link switching for regenerating payload satellites and EPS integration.

[0049] Figure 6This is an example of a method 600 for feeder link handover in an NTN communication environment performed by a base station according to embodiments of the present disclosure. The method 600 for feeder link handover in an NTN communication environment performed by a base station is used to implement some embodiments of the present disclosure. Some embodiments of the present disclosure can be implemented in the method 600 for feeder link handover in an NTN communication environment performed by a base station using any appropriately configured hardware and / or software. In some embodiments, the method 600 for feeder link handover in an NTN communication environment performed by a base station includes: operation 602, continuously monitoring the SCTP state; operation 604, when a disconnection of a first feeder link between a base station on a satellite and a first ground-based entity is detected based on the SCTP state, broadcasting a first message across the cell where the base station is located to indicate the disconnection of the first feeder link; operation 606, based on the SCTP state, triggering a TNL node on the satellite to release TNL resources allocated to the first ground-based entity and / or configuring a transmission association for a second feeder link between the base station on the satellite and a second ground-based entity before the disconnection of the first feeder link. This can resolve issues in existing technologies and other problems, and / or support feeder link switching for regenerable payload satellites integrated with EPS.

[0050] In some embodiments, if a first terrestrial entity predicts an impending disconnection of a first feeder link based on satellite ephemeris data, a base station receives a notification from the first terrestrial entity indicating the impending disconnection of the first feeder link. The base station then broadcasts a second message across the cell in which it resides to indicate the impending disconnection of the first feeder link. The base station initiates at least one procedure to release TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between the base station on the satellite and the second terrestrial entity prior to the impending disconnection of the first feeder link.

[0051] In some embodiments, the method further includes: enabling feeder link handover to trigger at least one TAU procedure. In some embodiments, enabling feeder link handover includes broadcasting at least one satellite ephemeris condition-related information, including the expected start time of the feeder link handover. In some embodiments, when the base station notifies the UE of an upcoming feeder link handover, the UE initiates at least one TAU procedure. In some embodiments, the at least one TAU procedure applies to a UE in ECM-IDLE state or ECM-CONNECTED state.

[0052] In some embodiments, at least one TAU procedure includes indicating a cell-barred state in the system minimum information. In some embodiments, at least one TAU procedure includes indicating a cell-barred state in the system minimum information. In some embodiments, if a feeder link handover connects a base station to the same MME, the base station derives the MME address from at least one RRC parameter. In some embodiments, if a feeder link handover connects a base station to a new MME, the new MME is predefined. In some embodiments, if at least one TAU procedure is caused by a feeder link handover, the MME triggers a release procedure after at least one TAU procedure is completed.

[0053] Figure 7 An example of a terrestrial entity 700 according to an embodiment of this application is shown. The terrestrial entity 700 is used to implement some embodiments of this disclosure. Some embodiments of this disclosure can be implemented in the terrestrial entity 700 using any appropriately configured hardware and / or software. The terrestrial entity 700 includes a predictor 701 and a notifier 702. The predictor 701 is used to predict an impending feeder link disconnection based on satellite control data. The notifier 702 is used to directly notify the UE of feeder link switching information via signaling. This can solve problems in the prior art and other issues, and / or support feeder link switching for regenerating payload satellites integrated with EPS.

[0054] In some embodiments, the ground-based entity is an NTN gateway or an MME. For example, such as Figure 2 As shown, the ground-based entity can be NTN GW1 or MME1 and / or NTN GW2 or MME2. In some embodiments, the signaling is non-access stratum (NAS) signaling or satellite signaling.

[0055] For example, specifically, in some embodiments, if any terrestrial entity, such as an NTN gateway or MME, predicts an impending feeder link disconnection based on satellite control data, such as ephemeris information, the terrestrial entity can directly notify the UE via NAS signaling or other satellite signaling communication mechanisms. The MME can directly notify the UE of feeder link switching information via NAS signaling.

[0056] Figure 8An example of a terrestrial entity 800 according to an embodiment of this disclosure is shown. The terrestrial entity 800 is used to implement some embodiments of this disclosure. Some embodiments of this disclosure can be implemented in the terrestrial entity 800 using any appropriately configured hardware and / or software. The terrestrial entity 800 may include a memory 801, a transceiver 802, and a processor 803 coupled to the memory 801 and the transceiver 802. The processor 803 may be used to implement the functions, programs, and / or methods described herein. A layer of a wireless interface protocol may be implemented in the processor 803. The memory 801 is operatively coupled to the processor 803 and stores various information to operate the processor 803. The transceiver 802 is operatively coupled to the processor 803 and transmits and / or receives wireless signals. The processor 803 may include an ASIC, other chipsets, logic circuits, and / or data processing devices. The memory 801 may include ROM, RAM, flash memory, memory cards, storage media, and / or other storage devices. Transceiver 802 may include baseband circuitry for processing radio frequency signals. When this embodiment is implemented in software, the techniques described herein can be implemented by modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules may be stored in memory 801 and executed by processor 803. Memory 801 may be implemented within processor 803 or external to processor 803; in the latter case, memory 801 may be communicatively coupled to processor 803 in various ways known in the art.

[0057] In some embodiments, processor 803 is used to predict an impending feeder link disconnection based on satellite control data, and transceiver 802 is used to directly notify the UE of the feeder link switching information via signaling. This can solve problems in the prior art and other issues, and / or support feeder link switching for regenerating payload satellites integrated with EPS. In some embodiments, the ground-based entity is an NTN gateway or MME. For example, such as Figure 2 As shown, the ground-based entity can be NTNGW1 or MME1 and / or NTN GW2 or MME2. In some embodiments, the signaling is NAS signaling or satellite signaling.

[0058] Figure 9This is an example of a method 900 for feeder link handover performed by a terrestrial entity according to embodiments of the present disclosure. The method 900 for feeder link handover performed by a terrestrial entity is used to implement some embodiments of the present disclosure. Some embodiments of the present disclosure can be implemented in the method 900 for feeder link handover performed by a terrestrial entity using any appropriately configured hardware and / or software. In some embodiments, the method 900 for feeder link handover performed by a terrestrial entity includes: operation 902, whereby if the terrestrial entity predicts an impending feeder link disconnection based on satellite control data, the terrestrial entity directly notifies the UE of feeder link handover information via signaling. This can address problems in the prior art and other issues, and / or support feeder link handover for regenerating payload satellites integrated with EPS. In some embodiments, the terrestrial entity is an NTN gateway or MME. For example, such as... Figure 2 As shown, the ground-based entity can be NTNGW1 or MME1 and / or NTN GW2 or MME2. In some embodiments, the signaling is NAS signaling or satellite signaling.

[0059] The present disclosure proposes the following solution: In some examples, the eNB continuously monitors the SCTP status. Upon detecting a feeder link disconnection, the eNB broadcasts a "Feeder Link Unavailable Start" message across cells. This action also triggers the TNL nodes on the satellite to configure transport associations for the target NTN GW feeder link prior to the source NTN-GW feeder link disconnection, and to release TNL resources allocated to the disconnected NTN gateway.

[0060] In some examples, if any terrestrial entity, such as an NTN gateway or MME, predicts an impending feeder link disconnection based on satellite ephemeris data, that terrestrial entity notifies the eNB. The eNB then broadcasts the appropriate message and initiates procedures to release the relevant TNL resources and establish a new connection.

[0061] Some embodiments of this disclosure also describe methods and apparatus for enabling feeder link switching to trigger at least one TAU procedure. Basic parameters, invocation flow, and triggering conditions will be described in detail in subsequent examples of at least one TAU procedure for feeder link switching.

[0062] In some examples, the eNB broadcasts information about satellite ephemeris conditions, including the expected start time of the feeder link handover. After the handover, the UE reports back to the eNB upon completion.

[0063] In some examples, when a UE is notified of an upcoming feeder link handover, at least one TAU procedure is initiated. This procedure applies to UEs in ECM-IDLE or ECM-CONNECTED states. The procedure involves several steps, including indicating a cell-barrier state in the system's minimum information (MIB, SIB1, or other SIBs) to prevent new connections during handover.

[0064] In some examples, if the switch connects the eNB to the same MME, the eNB derives the MME address from the existing RRC parameters. Otherwise, a new MME is predefined. Specifically, in some examples, a new MME is selected based on the MME selection function in TS 23.401.

[0065] In some examples, if the TAU is caused by a feeder link switchover, the MME can trigger an S1 release procedure after the TAU is completed. This is especially true if the TAU request message includes a "feeder link switchover started" indication, resulting in the release of the S1-AP connection between the eNB and the old MME.

[0066] Example of at least one TAU procedure for feeder link switching Figure 10 The call flow and system changes for a TAU without changes to the serving GW (SGW) are shown.

[0067] In some examples, in step 0, the eNB continuously monitors the SCTP status. Upon detecting a feeder link disconnection, the eNB broadcasts a "Feeder Link Unavailable Start" message across cells. This action also triggers the TNL node on the satellite to configure transmission associations for the target NTN GW feeder link prior to the source NTN-GW feeder link disconnection.

[0068] In some examples, in step 1, the feeder link switching triggers the UE to initiate the TAU procedure.

[0069] In some examples, in step 2, the UE initiates the TAU procedure by sending a TAU request to the eNodeB. In addition to the general parameters described in section 5.3.3.1 of TS23.401, the TAU request also includes "start of feeder link handover".

[0070] In some examples, in step 3, the eNodeB derives the MME address from the RRC parameters carrying the old GUMMEI. In cases such as... Figure 1 In the case of the same MME shown, the same MME will be used. In the case of... Figure 2 In the case of different MMEs shown, since the MME may no longer be associated with the eNodeB, the eNodeB selects a new MME as described in Clause 4.3.8.3 of TS 23.401.

[0071] In some examples, if the switch connects the eNB to the same MME, the eNB derives the MME address from the existing RRC parameters. If the eNB is not connected to the same MME, a new MME is selected according to the MME selection function in TS 23.401.

[0072] In some examples, steps 4 through 19, as specified in Clause 5.3.3.1 of TS 23.401 for TAUs with SGW changes and Clause 5.3.3.2 for TAUs without SGW changes, will follow the standard TAU procedure.

[0073] In some examples, in step 20, the MME sends a TAU acceptance with an indication of feeder link switching.

[0074] In some examples, in step 20a, the MME associated with the source NTN GW releases the logical signaling connection by issuing an S1-AP: S1 UE Context Release command.

[0075] In some examples, in step 20b, the eNodeB uses S1-AP: S1 UE context release complete to confirm. The legacy MME also releases the TNL resources allocated to the disconnected NTN gateway.

[0076] In some examples, in step 20c, the new MME associated with the target NTN GW notifies the eNodeB that the feeder link handover is complete. The eNodeB removes the cell that was banned due to the handover from the banned cell list and releases the associated TNL resources of the source NTN GW.

[0077] In some examples, in step 21, if the UE acknowledges receipt of a TAU completion message by returning it to the MME, the message may include an indication of feeder link switching.

[0078] Some embodiments of this disclosure support feeder link handover for regenerating payload satellites and EPS integration. Without the proposed procedure, the onboard eNB cannot associate with the MME at the target NTN GW, which will further generate unwanted signaling overhead on both the eNB and the MME, as well as additional UE power consumption. These factors lead to prolonged service interruptions and a degraded overall user experience.

[0079] Some embodiments offer the following commercial benefits: 1. Solving problems and other issues in the prior art. 2. Supporting feeder link switching for regenerable payload satellites integrated with EPS. 3. Improving the overall user experience. 4. Providing good communication performance. 5. Providing high reliability. Some embodiments of this disclosure can be used in many applications. Some embodiments of this disclosure are used by chipset suppliers, video system development suppliers, automobile manufacturers including cars, trains, trucks, buses, bicycles, motorcycles, helmets, etc., drones (unmanned aerial vehicles), smartphone manufacturers, communication equipment for public safety, and AR / VR / MR device manufacturers for purposes such as gaming, conferences / seminars, and education. Some embodiments of this disclosure are combinations of "technologies / processes" that can be adopted in video standards to create end products. Some embodiments of this disclosure propose technical mechanisms. At least one proposed solution, method, system, and apparatus of some embodiments of this disclosure can be used with current and / or new / future standards for communication systems (such as UEs, base stations, and / or communication systems). Compatible products follow at least one proposed solution, method, system, and apparatus of some embodiments of this disclosure. The proposed solutions, methods, systems, and apparatus are widely used in UEs, base stations, and / or communication systems. By utilizing the implementation of at least one proposed solution, method, system, and apparatus according to some embodiments of this disclosure, at least one modification to the method and apparatus for feeder link switching in the NTN communication environment is considered for standardization.

[0080] Figure 11 This is an example of a computing device 1100 according to an embodiment of the present disclosure. Any suitable computing device can be used to perform the operations described herein. For example, Figure 11 This demonstrates that it can be implemented using any appropriately configured hardware and / or software. Figures 1 to 10 Examples of computing devices 1100 in some embodiments are provided. In some embodiments, computing device 1100 may include processor 1112, processor 1112 being communicatively coupled to memory 1114 and executing computer-executable program code and / or accessing information stored in memory 1114. Processor 1112 may include a microprocessor, application-specific integrated circuit (“ASIC”), state machine, or other processing device. Processor 1112 may include any of a plurality of processing devices, including one processing device. Such a processor may include a computer-readable medium storing instructions, or may communicate with a computer-readable medium storing instructions that, when executed by processor 1112, cause the processor to perform the operations described herein.

[0081] Memory 1114 may include any suitable non-transitory computer-readable medium. Computer-readable media may include any electronic, optical, magnetic, or other storage device capable of providing computer-readable instructions or other program code to a processor. Non-limiting examples of computer-readable media include disks, memory chips, ROM, RAM, ASICs, configured processors, optical storage devices, magnetic tape or other magnetic storage devices, or any other medium from which a computer processor may read instructions. Instructions may include processor-specific instructions generated by a compiler and / or interpreter from code written in any suitable computer programming language, including, for example, C, C++, C#, Visual Basic, Java, Python, Perl, JavaScript, and ActionScript.

[0082] The computing device 1100 may also include a bus 1116. The bus 1116 may communicatively couple one or more components of the computing device 1100. The computing device 1100 may also include multiple external or internal devices, such as input or output devices. For example, the computing device 1100 is shown having an input / output (I / O) interface 1118 that can receive input from one or more input devices 1120 or provide output to one or more output devices 1122. One or more input devices 1120 and one or more output devices 1122 may be communicatively coupled to the I / O interface 1118. The communicative coupling may be implemented in any suitable manner (e.g., via a printed circuit board connection, via a cable connection, via wireless communication, etc.). Non-limiting examples of the input device 1120 include a touchscreen (e.g., one or more cameras for imaging a touch area or a pressure sensor for detecting pressure changes caused by a touch), a mouse, a keyboard, or any other device capable of generating input events in response to physical actions of a user of the computing device. Non-limiting examples of output device 1122 include a liquid crystal display (LCD) screen, an external monitor, a speaker, or any other device that can be used to display or otherwise present the output generated by the computing device.

[0083] The computing device 1100 can execute program code that configures the processor 1112 to perform the above-mentioned... Figures 1 to 10 One or more operations are described in some embodiments. The program code may reside in memory 1114 or any suitable computer-readable medium and may be executed by processor 1112 or any other suitable processor.

[0084] The computing device 1100 may also include at least one network interface device 1124. The network interface device 1124 may include any device or group of devices suitable for establishing wired or wireless data connections to one or more data networks 1128. Non-limiting examples of the network interface device 1124 include Ethernet adapters, modems, etc. The computing device 1100 can transmit messages as electrical or optical signals via the network interface device 1124.

[0085] Figure 12 This is a block diagram of an example communication system 1200 according to an embodiment of the present disclosure. The embodiments described herein can be implemented in the communication system 1200 using any suitably configured hardware and / or software. Figure 12 A communication system 1200 is shown, which includes a radio frequency (RF) circuit 1210, a baseband circuit 1220, an application circuit 1230, a memory / storage device 1240, a display 1250, a camera 1260, a sensor 1270, and an input / output (I / O) interface 1280, all of which are at least coupled to each other as shown.

[0086] Application circuitry 1230 may include, for example, but not limited to, circuitry of one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (such as graphics processors, application processors). The processor may be coupled to a memory / storage device and used to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system. Communication system 1200 may execute program code that configures application circuitry 1230 to perform the above-mentioned... Figures 1 to 10 One or more operations are described in some embodiments. The program code may reside in application circuit 1230 or any suitable computer-readable medium and may be executed by application circuit 1230 or any other suitable processor.

[0087] The baseband circuit 1220 may include, for example, but not limited to, circuitry of one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuit can handle various wireless control functions that enable communication with one or more wireless networks via RF circuitry. These wireless control functions may include, but are not limited to, signal modulation, encoding, decoding, and radio frequency shifting. In some embodiments, the baseband circuit can provide communication compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuit can support communication with the evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area networks (WMAN), WLANs, and wireless personal area networks (WPANs). Embodiments where the baseband circuit is configured to support wireless communication using more than one wireless protocol may be referred to as a multi-mode baseband circuit.

[0088] In various embodiments, baseband circuit 1220 may include circuitry that operates using signals strictly considered not to be in the baseband frequency range. For example, in some embodiments, the baseband circuitry may include circuitry that operates using signals having an intermediate frequency (IF) between the baseband frequency and the radio frequency (RF). RF circuitry 1210 enables communication with a wireless network using modulated electromagnetic radiation over a non-solid-state medium. In various embodiments, RF circuitry may include switches, filters, amplifiers, etc., to facilitate communication with a wireless network. In various embodiments, RF circuitry 1210 may include circuitry that operates using signals strictly considered not to be in the radio frequency range. For example, in some embodiments, RF circuitry may include circuitry that operates using signals having an intermediate frequency (IF) between the baseband frequency and the radio frequency.

[0089] In various embodiments, the above regarding Figures 1 to 10The transmitter circuitry, control circuitry, or receiver circuitry discussed in some embodiments may be wholly or partially embodied in one or more of the RF circuitry, baseband circuitry, and / or application circuitry. As used herein, “circuit” may refer to, be part of, or may include: an ASIC, electronic circuitry, processor (shared, dedicated, or grouped) and / or memory (shared, dedicated, or grouped), combinational logic circuitry, and / or other suitable hardware components that provide the described functionality, executing one or more software or firmware programs. In some embodiments, electronic device circuitry may be implemented in one or more software or firmware modules, or the functionality associated with the circuitry may be implemented by one or more software or firmware modules. In some embodiments, some or all of the components of the baseband circuitry, application circuitry, and / or memory / storage device may be implemented together on a system-on-chip (SOC). Memory / storage device 1240 may be used to load and store, for example, data and / or instructions for the system. Memory / storage device for one embodiment may include any combination of suitable volatile memory (such as dynamic random access memory, DRAM) and / or non-volatile memory (such as flash memory).

[0090] In various embodiments, I / O interface 1280 may include one or more user interfaces designed to enable user interaction with the system and / or peripheral component interfaces designed to enable peripheral components to interact with the system. User interfaces may include, but are not limited to, physical keyboards or keypads, touchpads, speakers, microphones, etc. Peripheral component interfaces may include, but are not limited to, non-volatile memory ports, universal serial bus (USB) ports, audio jacks, and power interfaces. In various embodiments, sensor 1270 may include one or more sensing devices to determine environmental conditions and / or location information relevant to the system. In some embodiments, sensors may include, but are not limited to, gyroscope sensors, accelerometers, proximity sensors, ambient light sensors, and positioning units. Positioning units may also be part of or interact with baseband and / or RF circuitry to communicate with components of a positioning network, such as Global Positioning System (GPS) satellites.

[0091] In various embodiments, display 1250 may include a display, such as a liquid crystal display (LCD) and a touchscreen display. In various embodiments, communication system 1200 may be a mobile computing device, such as, but not limited to, a laptop, tablet, netbook, ultrabook, smartphone, AR / VR glasses, etc. In various embodiments, the system may have more or fewer components and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

[0092] Those skilled in the art will understand that each unit, algorithm, and step described and disclosed in the embodiments of this disclosure is implemented using electronic hardware or a combination of software and electronic hardware for a computer. Whether a function operates in hardware or software depends on the application conditions and the design requirements of the technical solution. Those skilled in the art can implement the functionality of each specific application in different ways, and such implementations should not exceed the scope of this disclosure. Those skilled in the art will understand that since the working processes of the above-described systems, devices, and units are substantially the same, the working processes of the systems, devices, and units in the above embodiments can be referred to. For ease of description and simplicity, these working processes will not be described in detail.

[0093] It is understood that the systems, devices, and methods disclosed in the embodiments of this disclosure can be implemented in other ways. The above embodiments are merely exemplary. The division of units is based solely on logical function, and other divisions exist in the implementation. Multiple units or components may be combined or integrated in another system. It is also possible to omit or skip some features. On the other hand, the mutual coupling, direct coupling, or communication coupling shown or discussed operates indirectly or communicatively through some ports, devices, or units in an electrical, mechanical, or other kind of manner.

[0094] The units used for explanation as separate components may be physically separate or not. The units used for display may be physical units or not, i.e., located in one place or distributed across multiple network units. Some or all of the units are used depending on the purpose of the embodiment. Furthermore, each functional unit in each embodiment may be integrated into a physically independent processing unit, or it may be integrated into a processing unit with two or more units.

[0095] If software functional units are implemented, used, and sold as products, they can be stored in a readable storage medium within a computer. Based on this understanding, the technical solutions proposed in this disclosure can be implemented substantially or partially as software products. Alternatively, a portion of a technical solution beneficial to conventional technology can be implemented as a software product. The software product in the computer is stored in a storage medium that includes multiple commands for a computing device (such as a personal computer, server, or network device) to execute all or some of the steps disclosed in the embodiments of this disclosure. The storage medium includes a USB flash drive, external hard drive, ROM, RAM, floppy disk, or other types of media capable of storing program code.

[0096] While this disclosure has been described in conjunction with embodiments that are considered to be the most practical and preferred, it should be understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements made without departing from the broadest interpretation of the appended claims.

Claims

1. A method for feeder link handover performed by a base station located in a non-terrestrial network (NTN) communication environment, comprising: Continuously monitor the status of the Stream Control Transport Protocol (SCTP); When a first feeder link between a base station on a satellite and a first ground-based entity is detected as disconnected based on the SCTP status, a first message is broadcast across the cell where the base station is located to indicate the disconnection of the first feeder link; as well as Based on the SCTP state, the Transmission Network Layer (TNL) node on the satellite is triggered to release the TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between the base station on the satellite and the second terrestrial entity before the first feeder link is disconnected.

2. The method according to claim 1, wherein, If the first terrestrial entity predicts an impending disconnection of the first feeder link based on satellite ephemeris data, the base station receives a notification from the first terrestrial entity indicating the impending disconnection of the first feeder link. The base station then broadcasts a second message across the cell in which it resides to indicate the impending disconnection of the first feeder link. The base station initiates at least one procedure to release the TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between the base station on the satellite and the second terrestrial entity prior to the impending disconnection of the first feeder link.

3. The method according to claim 1 or 2, further comprising: Enable feeder link switching to trigger at least one Tracking Area Update (TAU) procedure.

4. The method according to claim 3, wherein, Enabling the feeder link switch includes broadcasting information related to at least one satellite ephemeris condition, including the expected start time of the feeder link switch.

5. The method according to claim 4, wherein, When the base station notifies the UE of an upcoming feeder link handover, the UE initiates at least one TAU procedure.

6. The method according to claim 5, wherein, The at least one TAU procedure applies to the UE in the Evolved Packet System (EPS) Connection Management (ECM)-IDLE state or the ECM-CONNECTED state.

7. The method according to claim 5 or 6, wherein, The at least one TAU procedure includes indicating the cell prohibition state in the system minimum information.

8. The method according to any one of claims 3 to 7, wherein, The at least one TAU procedure includes indicating the cell prohibition state in the system minimum information.

9. The method according to any one of claims 3 to 8, wherein, If the feeder link handover connects the base station to the same Mobility Management Entity (MME), the base station derives the MME address from at least one Radio Resource Control (RRC) parameter.

10. The method according to any one of claims 3 to 9, wherein, If the feeder link switch connects the base station to a new MME, then the new MME is predefined.

11. The method according to claim 9 or 10, wherein, If the at least one TAU process is caused by the feeder link switching, the MME triggers a release process after the at least one TAU process is completed.

12. A base station installed in a non-terrestrial network (NTN) communication environment, comprising: A monitor used to continuously monitor the status of the Stream Control Transport Protocol (SCTP); A transceiver is configured to broadcast a first message across the cell where the base station is located to indicate the disconnection of the first feeder link when the monitor detects a disconnection of the first feeder link between the base station on the satellite and the first ground-based entity based on the SCTP status. as well as A trigger, configured to, based on the SCTP state, trigger the Transport Network Layer (TNL) node on the satellite to release TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between the base station on the satellite and the second terrestrial entity prior to the disconnection of the first feeder link.

13. The base station according to claim 12, wherein, If the first terrestrial entity predicts an impending disconnection of the first feeder link based on satellite ephemeris data, the transceiver receives a notification from the first terrestrial entity indicating the impending disconnection of the first feeder link. The transceiver then broadcasts a second message across the cell where the base station is located to indicate the impending disconnection of the first feeder link. The trigger initiates at least one procedure to release the TNL resources allocated to the first terrestrial entity and / or configure the transmission association of the second feeder link between the base station on the satellite and the second terrestrial entity prior to the impending disconnection of the first feeder link.

14. The base station according to claim 12 or 13, wherein, The trigger is also used to enable feeder link switching to trigger at least one Tracking Area Update (TAU) procedure.

15. The base station according to claim 14, wherein, The transceiver is also used to broadcast information related to at least one satellite ephemeris condition, including the expected start time of the feeder link switch.

16. The base station according to claim 15, wherein, When the transceiver notifies the UE of an upcoming feeder link switch, the UE initiates at least one TAU procedure.

17. The base station according to claim 16, wherein, The at least one TAU procedure applies to the UE in the Evolved Packet System (EPS) Connection Management (ECM)-IDLE state or the ECM-CONNECTED state.

18. The base station according to claim 16 or 17, wherein, The at least one TAU procedure includes indicating the cell prohibition state in the system minimum information.

19. The base station according to any one of claims 14 to 18, wherein, The at least one TAU procedure includes indicating the cell prohibition state in the system minimum information.

20. The base station according to any one of claims 14 to 19, wherein, If the feeder link switch connects the base station to the same Mobility Management Entity (MME), the trigger derives the MME address from at least one Radio Resource Control (RRC) parameter.

21. The base station according to any one of claims 14 to 20, wherein, If the feeder link switch connects the base station to a new MME, then the new MME is predefined.

22. The base station according to claim 20 or 21, wherein, If the at least one TAU process is caused by the feeder link switching, the MME triggers a release process after the at least one TAU process is completed.

23. A base station, comprising: Memory; transceiver; as well as A processor coupled to the memory and the transceiver; The base station is used to perform the method according to any one of claims 1 to 11.

24. A method for feeder link switching performed by a ground-based entity, comprising: If the ground-based entity predicts that the feeder link is about to be disconnected based on satellite control data, the ground-based entity will directly notify the user equipment (UE) of the feeder link switching information via signaling.

25. The method according to claim 24, wherein, The ground-based entity is a non-terrestrial network (NTN) gateway or a mobility management entity (MME).

26. The method according to claim 24, wherein, The signaling is non-access stratum (NAS) signaling or satellite signaling.

27. A ground-based entity, comprising: Predictor used to predict when a feeder link is about to break based on satellite control data; as well as The notifier is used to directly notify the user equipment (UE) of feeder link switching information via signaling.

28. The ground-based entity according to claim 27, wherein, The ground-based entity is a non-terrestrial network (NTN) gateway or a mobility management entity (MME).

29. The ground-based entity according to claim 27, wherein, The signaling is non-access stratum (NAS) signaling or satellite signaling.

30. A ground-based entity, comprising: Memory; transceiver; as well as A processor coupled to the memory and the transceiver; The base station is used to perform the method according to any one of claims 24 to 26.

31. A non-transitory machine-readable storage medium having instructions stored thereon that, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 24 to 26.

32. A chip, comprising: A processor for calling and running a computer program stored in memory to cause a device on which the chip is mounted to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 24 to 26.

33. A computer-readable storage medium storing a computer program, wherein, The computer program causes the computer to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 24 to 26.

34. A computer program product comprising a computer program, wherein, The computer program causes the computer to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 24 to 26.

35. A computer program, wherein, The computer program causes the computer to perform the method according to any one of claims 1 to 11 or the method according to any one of claims 24 to 26.

Images