Method for sharing system information via sidelink and device therefor

Abstract

The present document relates to a method for sharing system information (SI) via a sidelink, and a device therefor. To this end, a method by which a first user equipment (UE) communicates with a network comprises the steps in which the first user equipment: receives a master information block (MIB) among system information (SI) from a specific cell of the network; receives system information block (SIB) 1 on the basis of the MIB information; and transmits the SI to a second user equipment via a sidelink when it is confirmed that the specific cell is a non-terrestrial network (NTN) cell through the information about SIB 1.

Description

Method for sharing system information through sidelink and device therefor

[0001] The following description relates to a method for performing communication by sharing SI (System Information) information through a sidelink and a device therefor.

[0002] Wireless communication systems utilize a variety of technologies, including LTE, LTE-Advanced, and WiFi, and 5G is also included. The three main usage scenarios for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC). Some use cases may require optimization across multiple areas, while others may focus on just a single Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0003] Meanwhile, standardization of NTN (Non-Terrestrial Network) is in full swing starting with Release 17 during the 5G standardization process.

[0004] Figure 1 is a drawing to explain the concept of NTN.

[0005] Specifically, FIG. 1 is a drawing citing the concept of various types of NTN introduced in “5G from Space: An Overview of 3GPP Non-Terrestrial Networks” (authors, Xingqin Lin et al.), and NTN may include a satellite network (110), a high-latitude platform station (120) as an IMT base station, an air-ground network (130), etc.

[0006] These various types of networks can provide efficient communication services to remote areas (140) by utilizing wide coverage as conceptualized and illustrated in Fig. 1, and have the advantage of being able to provide efficient communication services to user equipment (UE) such as UAVs (150).

[0007] However, communication between NTN and UE may experience communication delay due to high altitude, and for example, there may be an inevitable delay in UE obtaining SI information from NTN and / or high battery consumption may be a disadvantage.

[0008] In order to solve the above-described problem, one aspect of the present invention provides a method and a device for performing communication by sharing SI information acquired by a specific UE with another UE through a side link.

[0009] Specifically, we propose a method for a specific UE to determine whether a cell is an NTN cell through a Master Information Block (MIB) and a number of subsequent System Information Blocks (SIBs) received from the network, and accordingly, which SIBs to share through a sidelink.

[0010] Meanwhile, in embodiments of the present invention, we propose an operation mechanism for how to perform communication with an NTN when an SIB essential for NTN access is not secured from the standpoint of a UE receiving SI.

[0011] In addition, in one embodiment of the present invention, it is intended to explain in what cases a UE receiving SI will request SI for an NTN cell.

[0012] In addition, embodiments of the present invention will explain various situations in which the SI information described above is shared via sidelink.

[0013] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0014] In one aspect of the present invention for solving the above-described problem, a method for performing communication between a first user equipment (UE) and a network in a mobile communication system is proposed, the method comprising: receiving a Master Information Block (MIB) among System Information (SI) from a specific cell of the network; receiving a System Information Block (SIB) 1 based on the MIB information; and transmitting the SI to a second user equipment (UE) via a sidelink when it is confirmed through the information of the SIB 1 that the specific cell is a Non-Terrestrial Network (NTN) cell.

[0015] At this time, the SI transmitted to the second user device may include SIB 19 essential for NTN access, and when the second user device determines that the specific cell is an NTN cell and does not receive SIB 19 from the side link, the second user device may transmit a message requesting the SIB 19 to the first user device through the side link.

[0016] In addition, the second user device may include, when the specific cell is an NTN cell and SIB 19 is received from the sidelink, driving a first timer having an NTN uplink synchronization valid period from a time unit indicated by epochTime, and transmitting the SIB 19 request message to the first user device through the sidelink when the SIB 19 is not re-received before the first timer expires.

[0017] Preferably, the message requesting the SIB 19 may be transmitted via a side link only when the RSRP (Reference Signal Received Power) or RSRQ (Reference Signal Received Quality) of the NTN cell measured by the second user device is below a predetermined standard.

[0018] Additionally, the message requesting the SIB 19 may be transmitted via a sidelink when the second user device operates in a power saving mode.

[0019] In addition, transmitting the SI to the second user device via the side link may be done by transmitting only SI for NTN cells for which RSRP or RSRQ measured through one or more of SSB (Synchronization Signal Block) or CSI-RS (Channel State Information - Reference Signal) received from a plurality of NTN cells is greater than or equal to a predetermined standard.

[0020] In the above-described embodiments, the first user device and the second user device may be positioned in platooning vehicles, and the first user device may be positioned in a Leading Vehicle (LV) and the second user device may be positioned in a Following Vehicle (FV).

[0021] Additionally, the NTN is located on a low-orbit satellite, and the first user device can be determined based on movement path information of the low-orbit satellite.

[0022] Additionally, the first user device may be a U2N (User-to-Network) relay user device, and the second user device may correspond to a remote user device.

[0023] In addition, the first user device and the second user device belong to one user device group, and the first user device can correspond to a group head user device.

[0024]

[0025] In another aspect of the present invention for solving the above-described problem, a method for a network to perform communication with a first user equipment (UE) in a mobile communication system is proposed, comprising: transmitting a Master Information Block (MIB) of System Information (SI) to the first user equipment through a specific cell of the network; and transmitting a System Information Block (SIB) 1 to the first user equipment based on the MIB information, wherein the network indicates through information of the SIB 1 that the specific cell is a Non-Terrestrial Network (NTN) cell, and instructs the first user equipment to share the SI to a second user equipment through a sidelink.

[0026] At this time, the SI transmitted to the second user device includes SIB 19 essential for NTN access, and the SIB 19 may include an NTN configuration (NTN-Config) information element.

[0027] Accordingly, instructing the SI to be shared via the sidelink may also be performed via a specific field of the NTN configuration (NTN-Config) information element.

[0028] In the embodiments described above, the first user device and the second user device may be positioned in platooning vehicles, and the first user device may be positioned in a Leading Vehicle (LV) and the second user device may be positioned in a Following Vehicle (FV).

[0029] Additionally, the NTN is located on a low-orbit satellite, and the network may determine the first user device based on the movement path information of the low-orbit satellite.

[0030] Additionally, the first user device is a U2N (User-to-Network) relay user device, and the second user device can correspond to a remote user device.

[0031] Additionally, the first user device and the second user device belong to one user device group, and the first user device may correspond to a group head user device.

[0032] Meanwhile, in another aspect of the present invention, a device operating as a first user equipment (UE) performing communication with a network in a mobile communication system is proposed, the device comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: receiving, by the first user equipment, a Master Information Block (MIB) among SI (System Information) from a specific cell of the network; receiving a System Information Block (SIB) 1 based on the MIB information; and transmitting, by the first user equipment, the SI to a second user equipment via a sidelink when it is determined through information of the SIB 1 that the specific cell is a Non-Terrestrial Network (NTN) cell.

[0033] In another aspect of the present invention, a network for performing communication with a first user equipment (UE) in a mobile communication system comprises at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include transmitting a Master Information Block (MIB) of System Information (SI) to the first user equipment through a specific cell of the network; and transmitting a System Information Block (SIB) 1 to the first user equipment based on the MIB information.

[0034] We propose a network in which the network indicates that the specific cell is a Non-Terrestrial Network (NTN) cell through the information of the SIB 1, and instructs the first user device to share the SI with the second user device via a sidelink.

[0035] According to the embodiments of the present invention as described above, communication can be performed by sharing SI information acquired by a specific UE with another UE through a side link.

[0036] Specifically, it presents a criterion for determining whether a cell is an NTN cell through which of the MIB (Master Information Block) and several subsequent SIBs (System Information Blocks) received by a specific UE from the network, and accordingly specifies which SIBs to share through the sidelink, thereby increasing communication efficiency.

[0037] Meanwhile, in embodiments of the present invention, when SIB, which is essential for NTN access, is not secured from the standpoint of a UE sharing SI, an operation mechanism for performing communication with NTN is specifically proposed, thereby enabling stable operation of NTN communication.

[0038] In addition, embodiments of the present invention provide for various situations in which the SI information described above is shared as a side link, and can be utilized in various situations such as platooning, low-orbit satellites, U2N relay, and UE grouping.

[0039] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0040] Figure 1 is a drawing to explain the concept of NTN.

[0041] FIG. 2 and FIG. 3 are diagrams for explaining the concept of sharing SI information through a side link according to embodiments of the present invention.

[0042] Figure 4 is a drawing specifically explaining the SI acquisition procedure of UE.

[0043] FIG. 5 is a diagram for explaining a concept in which NTN cell-related SI information is shared via a side link according to one embodiment of the present invention.

[0044] FIGS. 6 and 7 are drawings for explaining a method for a second user device to secure an SIB essential for NTN access according to embodiments of the present invention.

[0045] FIG. 8 is a diagram illustrating a procedure for performing sidelink communication according to one embodiment of the present invention.

[0046] FIG. 9 is a diagram for explaining application of SI sharing through side link in a platooning situation according to one embodiment of the present invention.

[0047] FIG. 10 is a diagram for explaining a situation in which a U2N Relay UE and a remote UE exist according to one embodiment of the present invention.

[0048] Figure 11 illustrates a wireless device to which the present technology can be applied.

[0049] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0050] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0051]

[0052] FIG. 2 and FIG. 3 are diagrams for explaining the concept of sharing SI information through a side link according to embodiments of the present invention.

[0053] Referring to FIG. 2, a first user device (UE1) can perform a procedure (S210) for obtaining SI (System Information) from a network, specifically, a gNB, and thereby receive a MIB and several SIBs.

[0054] In this embodiment, if the network satisfies the condition including NTN, it is proposed that UE 1 share the acquired SI with UE 2 and UE 3 (S220, S230). Since SI information includes information common to the entire cell rather than information for a specific UE, other UEs (UE 2 .. UE N) can communicate by utilizing the shared SI without a separate procedure for acquiring their own SI from the network, thereby reducing communication delay and power consumption.

[0055] As illustrated in FIG. 2, the SI update procedure of UE 2 .. UE N may be based on the SI shared from UE 1 via the sidelink as described above (S240). Of course, depending on the situation of UE 2 .. UE N, the SI update may be performed independently, but as described above, unnecessary delay and power consumption can be prevented through SI sharing via the sidelink.

[0056] In the embodiment illustrated in Fig. 3, unlike Fig. 2, it illustrates a case in which MIBs and SIBs are received separately.

[0057] Specifically, all UEs (UE 1, UE 2, ... UE N) can receive MIB directly from the gNB. MIB is the most basic SI for network access among SIs, and contains information required for receiving subsequent SIB 1. In the case of NR, it is transmitted through BCH (Broadcast Channel) in repetitions of 80 ms. Therefore, in this embodiment, unlike the embodiment of FIG. 2, MIB may be configured so that each UE receives it from its own gNB, and only subsequent SIBs are shared through sidelink.

[0058] That is, it is proposed that the first UE receives subsequent SIB 1 and other SIBs from the gNB (S320), and if the cell is an NTN cell, shares them with other UEs (UE 2, ..., UE N) via sidelink (S330, S340). Accordingly, SI updates of other UEs can be performed (S350).

[0059] In the embodiments described above with reference to FIGS. 2 and 3, the first UE shared the acquired SI with other UEs when the corresponding cell was an NTN cell. To this end, the SI acquisition procedure is specifically described below to examine how the first UE confirms that the corresponding cell is an NTN cell and what SI should be shared via the sidelink.

[0060]

[0061] Figure 4 is a drawing specifically explaining the SI acquisition procedure of UE.

[0062] According to the NR standard, for a UE in RRC_IDLE and RRC_INACTIVE states, it is required to receive MIB, SIB 1 to SIB 4, SIB 5 (if the UE supports E-UTRA), SIB 11 (if idle / inactive measurement is configured for the UE), SIB 12 (if the UE supports sidelink), SIB 13, SIB 14 (if the UE supports LTE V2X sidelink communication), SIB 15 (if the UE is configured to report disaster roaming related information), SIB 16 (if the UE supports slice-based cell reselection and has received NSAG information for cell reselection from upper layers), SIB 17 (if the UE utilizes TRS resources for power saving in RRC_IDLE and RRC_INACTIVE states) and SIB 19 (if the UE supports NR over NTN connection).

[0063] For a UE in RRC_CONNECTED state, the network can send specific system information to the UE via an RRC reconfiguration message.

[0064] Referring to FIG. 4, the UE can receive an MIB containing the most basic SI from the network and information for receiving subsequent SIB 1 (S410). As described above, this is periodically and repeatedly transmitted through the BCH, one of the Transport Channels, and in the physical layer, it can be transmitted through the PBCH (Physical Broadcast Channel) included in the SSB (Synchronization Signal Block) resource.

[0065] Based on the received MIB information, the UE can receive SIB 1 from the network (S420). According to the NR standard, SIB 1 can be transmitted over the DL-SCH, one of the Transport Channels, and then over the PDSCH (Physical Downlink Shared Channel) of the physical layer, at a 160 ms cycle or at various cycles within 160 ms.

[0066] SIB 1 may contain information related to the availability and scheduling of subsequent SIBs. This may include information such as whether subsequent SIBs are transmitted on-demand and which SIBs are mapped to SI messages. SIB 1 is cell-specific information, indicating whether the cell is an NTN cell.

[0067] Referring back to FIG. 4, a UE that has received up to SIB 1 may transmit a system information request message to the network to obtain the SIB required for operation (S430). In response, the network may transmit the SIB requested by the UE via a system information message (S440).

[0068] Among the SIBs following SIB 1, SIBs 12 to 14 required for sidelink communication and SIB 19 essential for NTN access are described.

[0069] [Table 1] shows the information elements included in SIB 12.

[0070] -- ASN1START-- TAG-SIB12-STARTSIB12-r16 ::= SEQUENCE {segmentNumber-r16 INTEGER (0..63),segmentType-r16 ENUMERATED {notLastSegment, lastSegment},segmentContainer-r16 OCTET STRING}SIB12-IEs-r16 ::= SEQUENCE {sl-ConfigCommonNR-r16 SL-ConfigCommonNR-r16,lateNonCriticalExtension OCTET STRING OPTIONAL,...,[[sl-DRX-ConfigCommonGC-BC-r17 SL-DRX-ConfigGC-BC-r17 OPTIONAL, -- Need Rsl-DiscConfigCommon-r17 SL-DiscConfigCommon-r17 OPTIONAL, -- Need Rsl-L2U2N-Relay-r17 ENUMERATED {enabled} OPTIONAL, -- Need Rsl-NonRelayDiscovery-r17 ENUMERATED {enabled} OPTIONAL, -- Need Rsl-L3U2N-RelayDiscovery-r17 ENUMERATED {enabled} OPTIONAL, -- Need Rsl-TimersAndConstantsRemoteUE-r17 UE-TimersAndConstantsRemoteUE-r17 OPTIONAL -- Need R]]}SL-ConfigCommonNR-r16 ::= SEQUENCE {sl-FreqInfoList-r16 SEQUENCE (SIZE (1..maxNrofFreqSL-r16)) OF SL-FreqConfigCommon-r16 OPTIONAL, -- Need Rsl-UE-SelectedConfig-r16 SL-UE-SelectedConfig-r16 OPTIONAL, -- Need Rsl-NR-AnchorCarrierFreqList-r16 SL-NR-AnchorCarrierFreqList-r16 OPTIONAL, -- Need Rsl-EUTRA-AnchorCarrierFreqList-r16 SL-EUTRA-AnchorCarrierFreqList-r16 OPTIONAL, -- Need Rsl-RadioBearerConfigList-r16 SEQUENCE (SIZE (1..maxNrofSLRB-r16)) OF SL-RadioBearerConfig-r16 OPTIONAL, -- Need Rsl-RLC-BearerConfigList-r16 SEQUENCE (SIZE (1..maxSL-LCID-r16)) OF SL-RLC-BearerConfig-r16 OPTIONAL, -- Need Rsl-MeasConfigCommon-r16 SL-MeasConfigCommon-r16 OPTIONAL, -- Need Rsl-CSI-Acquisition-r16 ENUMERATED {enabled} OPTIONAL, -- Need Rsl-OffsetDFN-r16 INTEGER (1..1000) OPTIONAL, -- Need Rt400-r16 ENUMERATED {ms100, ms200, ms300, ms400, ms600, ms1000, ms1500, ms2000} OPTIONAL, -- Need Rsl-MaxNumConsecutiveDTX-r16 ENUMERATED {n1, n2, n3, n4, n6, n8, n16, n32} OPTIONAL, -- Need Rsl-SSB-PriorityNR-r16 INTEGER (1..8) OPTIONAL -- Need R}SL-NR-AnchorCarrierFreqList-r16 ::= SEQUENCE (SIZE (1..maxFreqSL-NR-r16)) OF ARFCN-ValueNRSL-EUTRA-AnchorCarrierFreqList-r16 ::= SEQUENCE (SIZE (1..maxFreqSL-EUTRA-r16)) OF ARFCN-ValueEUTRASL-DiscConfigCommon-r17 ::= SEQUENCE {sl-RelayUE-ConfigCommon-r17 SL-RelayUE-Config-r17,sl-RemoteUE-ConfigCommon-r17 SL-RemoteUE-Config-r17}-- TAG-SIB12-STOP-- ASN1STOP.

[0071]

[0072] Among the various information elements in the above [Table 1], the sidelink E-UTRA anchor carrier frequency list (sl-EUTRA-AnchorCarrierFreqList) and the sidelink-frequency information list (sl-FreqInfoList) are information elements that provide frequency information for performing sidelink communication in NR.

[0073] Additionally, the sidelink U2N (User-to-Network) relay (sl-L2U2N-Relay) is an information element indicating whether the relay supports a U2N relay as described below.

[0074]

[0075] Meanwhile, [Table 2] shows the information elements included in SIB 13.

[0076] -- ASN1START-- TAG-SIB13-STARTSIB13-r16 ::= SEQUENCE {sl-V2X-ConfigCommon-r16 OCTET STRING,dummy OCTET STRING,tdd-Config-r16 OCTET STRING,lateNonCriticalExtension OCTET STRING OPTIONAL,...}-- TAG-SIB13-STOP-- ASN1STOP

[0077] Specifically, among the information elements shown in [Table 2], Sidelink - V2X - Common Configuration (sl-V2X-ConfigCommon-r16) is an information element corresponding to SIB type 21 of the LTE standard and includes common system information for LTE V2X communication.

[0078] Meanwhile, [Table 3] shows the information elements included in SIB 14.

[0079] -- ASN1START-- TAG-SIB14-STARTSIB14-r16 ::= SEQUENCE {sl-V2X-ConfigCommonExt-r16 OCTET STRING,lateNonCriticalExtension OCTET STRING OPTIONAL,...}-- TAG-SIB14-STOP-- ASN1STOP

[0080] Specifically, among the information elements shown in [Table 3], Sidelink - V2X - Common Configuration Extension (sl-V2X-ConfigCommonExt-r16) is an information element corresponding to SIB type 26 of the LTE standard and includes extended system information for LTE V2X communication.

[0081] With respect to the above [Table 1] to [Table 3], the SIBs 13 to 15 described above may be referred to as SI required for sidelink communication. Therefore, the 'SI required for sidelink communication' hereinafter means the SIBs 13 to 15 described above based on the NR standard, or 'some' thereof. The meaning of 'some' is, for example, that in some cases, sidelink communication may be performed based on LTE V2X without needing to receive extended system information transmitted as SIB 14, while operating based on LTE V2X.

[0082]

[0083] Meanwhile, [Table 4] shows the information elements included in SIB 19 related to NTN communication.

[0084] -- ASN1START-- TAG-SIB19-STARTSIB19-r17 ::= SEQUENCE {ntn-Config-r17 NTN-Config-r17 OPTIONAL, -- Need Rt-Service-r17 INTEGER (0..549755813887) OPTIONAL, -- Need RreferenceLocation-r17 ReferenceLocation-r17 OPTIONAL, -- Need RdistanceThresh-r17 INTEGER(0..65525) OPTIONAL, -- Need Rntn-NeighCellConfigList-r17 NTN-NeighCellConfigList-r17 OPTIONAL, -- Need RlateNonCriticalExtension OCTET STRING OPTIONAL,...,[[ntn-NeighCellConfigListExt-v1720 NTN-NeighCellConfigList-r17 OPTIONAL -- Need R]]}NTN-NeighCellConfigList-r17 ::= SEQUENCE (SIZE(1..maxCellNTN-r17)) OF NTN-NeighCellConfig-r17NTN-NeighCellConfig-r17 ::= SEQUENCE {ntn-Config-r17 NTN-Config-r17 OPTIONAL, -- Need RcarrierFreq-r17 ARFCN-ValueNR OPTIONAL, -- Need RphysCellId-r17 PhysCellId OPTIONAL -- Need R}-- TAG-SIB19-STOP-- ASN1STOP

[0085] Among the various information elements in the above [Table 4], the NTN configuration (ntn-Config) information element may include ephemeris data, common TA parameters, k_offset, NTN uplink synchronization validity duration for UL sync information, and epoch time (epochTime) information.

[0086] Additionally, the NTN Neighbor Cell Configuration List (ntn-NeighCellConfigList) and NTN Neighbor Cell Configuration List Extension (ntn-NeighCellConfigListExt) information elements may indicate a list of NTN neighbor cells and the NTN configuration (ntn-Config) information element, carrier frequency, and physical cell ID of each neighbor cell.

[0087] The information of SIB 19 shown in [Table 4] above can be viewed as essential information elements for NTN connection.

[0088] As described above, in the SI information acquisition process illustrated in Fig. 4, SIBs other than SIB 1, such as SIBs 12 to 14 and SIB 19, can be secured in an on-demand form based on the UE's system information request message transmission (S430).

[0089] FIG. 5 is a diagram for explaining a concept in which NTN cell-related SI information is shared via a side link according to one embodiment of the present invention.

[0090] In this embodiment, the first UE first receives MIB among various SIs as described above from a specific cell of the network (S510), and can receive SIB 1 based on the received MIB information (S520).

[0091] In this embodiment, if the specific cell is an NTN cell as described above, it is proposed to share the SI information received with the second UE via a side link (S550). At this time, whether the specific cell is an NTN cell can be confirmed based on SIB 1 received in step S520 (S530).

[0092] The embodiment of FIG. 5 illustrates a case where, after confirming that the specific cell is an NTN cell (S530), subsequently received SIBs, particularly SIB 19 (S540), are transmitted to the second UE via a sidelink (S550). However, before determining whether the cell is an NTN cell (S530), the first UE may secure SIs including SIB 19 in advance, and, if it is confirmed that the cell is an NTN cell, may immediately share the SIs with the second UE.

[0093] In this embodiment, it is assumed that the first UE and the second UE have a PC5 interface formed in advance for sidelink connection. That is, the first UE and the second UE may have already formed a sidelink based on information from SIB 12 to SIB 14, and in some cases, if the second UE corresponds to a remote UE, the first UE may form a sidelink by transmitting the sidelink communication-related SIB received by the first UE to the second UE.

[0094]

[0095] FIGS. 6 and 7 are drawings for explaining a method for a second user device to secure an SIB essential for NTN access according to embodiments of the present invention.

[0096] In the embodiment described above with reference to FIG. 5, the SI (S550) transmitted to the second UE via the sidelink may include various SIs, including the MIB and SIB 1. In some cases, as described above with reference to FIG. 2, all SIs may be shared via the sidelink, as described above with reference to FIG. 3, the MIB may be directly transmitted to all UEs via the network, but only subsequent SIBs may be shared via the sidelink, or the MIB and SIB 1 may be directly transmitted to all UEs via the network, but only subsequent SIBs may be shared via the sidelink.

[0097] However, in this embodiment, we focus on securing SIB 19, which is essential for NTN access among shared SI, and propose the following mechanisms.

[0098] First, as illustrated in FIG. 6, the second UE can check whether the shared SI includes SIB 19 (S610). If the cell is an NTN cell and does not receive SIB 19 from the sidelink, the second UE can transmit a message requesting SIB 19 to the first UE via the sidelink (S620).

[0099] Accordingly, the first UE can reply with a response message including SIB 19 in response to the request message (S630). If, after sharing SI with the second UE via the sidelink (S550), an updated SIB 19 is received via the network (S540), it is preferable that the first UE respond based on the latest SIB 19 at the time of receiving the SIB 19 request message.

[0100] Meanwhile, in the embodiment of FIG. 7, it is assumed that the second UE receives SI from the first UE (S550), and the shared SI includes SIB 19.

[0101] In this way, when the second UE receives SIB 19 via sidelink, it is proposed to start a first timer having a validity duration for UL sync information of the NTN from a time unit (subframe in case of NR) indicated by the epoch time (epochTime) described above in relation to [Table 4] (S710). This is to manage the update cycle, since SIB 19 needs to be updated before the validity duration in order to maintain uplink synchronization for NTN access.

[0102] If SIB 19 is not re-received before the first timer expires (S730), the second UE may transmit an SIB 19 request message to the first UE via the sidelink (S740). Accordingly, the first UE may retransmit the latest SIB 19 information to the second UE via the sidelink at the time of receiving the SIB 19 request message (S750).

[0103] FIG. 7 illustrates a case where, after sharing SIB 19 with a second UE in step S550, an updated SIB 19 is received from the network (S720). In this case, the SIB 19 transmitted to the second UE in step S750 may be the SIB 19 received in step S720.

[0104]

[0105] In the embodiment according to the above-described Fig. 6 or Fig. 7, it is preferable that the message requesting SIB 19 be transmitted via the sidelink (S620, S740) only when the RSRP (Reference Signal Received Power) or RSRQ (Reference Signal Received Quality) of the NTN cell measured by the second UE is below a predetermined standard. For example, if the second UE is also in NTN connection with the NTN cell and the RSRP / RSRQ of the NTN cell is above a predetermined standard, it may be more efficient for the second UE to directly request SIB 19 from the NTN cell than to request it from the first UE via the sidelink.

[0106] Additionally, in the embodiment according to the above-described FIG. 6 or FIG. 7, transmitting a message requesting SIB 19 via a sidelink (S620, S740) may be configured to be performed when the second UE operates in a power saving mode. This is because, when the second UE operates in a power saving mode, power consumption may increase if the second UE directly transmits the SIB 19 request message to the network.

[0107] Meanwhile, in the above-described embodiments, the first UE transmitting SI to the second UE via the sidelink (S550) may be configured to transmit only SI for NTN cells for which RSRP or RSRQ measured via one or more of the SSB (Synchronization Signal Block) or CSI-RS (Channel State Information - Reference Signal) received from a plurality of NTN cells is above a predetermined standard. In other words, it may be efficient to share SI with a peer UE for a cell for which the quality of a beam observed by the first UE is above a predetermined level among a plurality of NTN cells.

[0108]

[0109] FIG. 8 is a diagram illustrating a procedure for performing sidelink communication according to one embodiment of the present invention.

[0110] The embodiment of FIG. 8 can be combined with various embodiments of the present invention. In various embodiments of the present invention, the "transmission mode" may be referred to as a "mode" or a "resource allocation mode." Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as the LTE transmission mode, and the transmission mode in NR may be referred to as the NR resource allocation mode.

[0111] Specifically, (a) of FIG. 8 represents terminal operation related to LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0112] Meanwhile, (b) of FIG. 8 shows terminal operation related to LTE transmission mode 2 or LTE transmission mode 4 or NR resource allocation mode 2.

[0113] Referring to (a) of FIG. 8, in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station can schedule SL resources to be used by the terminal for SL transmission (S8000). The scheduling information received at this time may also be transmitted via the aforementioned SIB 12 to SIB 14.

[0114] For example, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. The UL resources may include PUCCH resources and / or PUSCH resources. Additionally, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0115] A first terminal can receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. The CG resource can include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource can be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In addition, in this specification, a CG resource can be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station can transmit an RRC message including information related to the CG resource to the first terminal. In the case of a CG type 2 resource, the base station can transmit an RRC message including information related to the CG resource to the first terminal, and the base station can transmit a DCI related to activation or release of the CG resource to the first terminal.

[0116] In step S8010, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S8020, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S8030, the first terminal may receive a PSFCH (Physical Sidelink Feedback Channel) related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S8040, the first terminal may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the HARQ feedback information received from the second terminal. In addition, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a rule set in advance. The DCI may be DCI for scheduling the SL. The format of the DCI may be DCI format 3_0 or DCI format 3_1.

[0117] Table 5 shows an example of DCI for scheduling SL.

[0118] [Table 5]

[0119]

[0120] Referring to (b) of FIG. 8, in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, a terminal can determine an SL transmission resource within SL resources set by a base station / network or preset SL resources. The set SL resources or preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. The terminal can perform SL communication by selecting resources within the set resource pool. For example, the terminal can perform sensing and resource (re)selection procedures to select resources within a selection window. The sensing may be performed on a subchannel basis.

[0121] In step S8010, a first terminal that has selected a resource within a resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to a second terminal using the resource. In step S8020, the first terminal can transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S8030, the first terminal can receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0122] Referring to (a) or (b) of FIG. 8, a first terminal may transmit an SCI to a second terminal on a PSCCH. Alternatively, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, an SCI transmitted on a PSCCH may be referred to as a 1st SCI, a 1st SCI, a 1st-stage SCI, or a 1st-stage SCI format, and an SCI transmitted on a PSSCH may be referred to as a 2nd SCI, a 2nd SCI, a 2nd-stage SCI, or a 2nd-stage SCI format. For example, a 1st-stage SCI format may include SCI format 1-A, and a 2nd-stage SCI format may include SCI format 2-A and / or SCI format 2-B.

[0123]

[0124] Below, we describe various situations in which the SI information described above is utilized.

[0125] FIG. 9 is a diagram for explaining application of SI sharing through side link in a platooning situation according to one embodiment of the present invention.

[0126] The platooning control system (100) proposes a comprehensive concept including a lead vehicle (LV: 910) forming a platoon, one or more follower vehicles (FVs; 920, 930), and other vehicles (Potential FVs; 940, 950) that have not yet joined / are unable to join the platoon. As illustrated in Fig. 9, V2V (Vehicle-to-Vehicle) communication can be performed between the vehicles, and V2I (Vehicle-to-Infrastructure) communication can be performed with the back office that manages the platoon.

[0127] The LV (910) and one or more FVs (920, 930) that constitute the platoon are managed by the platooning management control function (Platooning Manoeuvre Control Function), and the joining and / or leaving of the PFV can be managed by the platooning operation control function (Platooning Operation Control Function).

[0128] In this situation, it can be assumed that the first UE and the second UE described in the above-described embodiments are located in platooning vehicles (910, 920, 930, 940, 950), respectively. At this time, the first UE is located in the LV (910) of FIG. 9 and obtains SI directly from the network, and can share the SI obtained in this way with the second UE located in the FV (920, 930) or the vehicle (940, 950) that wants to join the platooning, via a V2V-style sidelink.

[0129]

[0130] FIG. 10 is a diagram for explaining a situation in which a U2N Relay UE and a remote UE exist according to one embodiment of the present invention.

[0131] A U2N relay situation refers to a situation where a remote UE has difficulty communicating directly with the network (specifically, gNB) and receives the relevant information through a U2N Relay UE.

[0132] That is, in the embodiment described above, the UE that obtains SI information from the gNB on its own is a U2N Relay UE, and the UE that receives it through a side link can respond in the case where it is a remote UE.

[0133] In step 1 of FIG. 10, the U2N remote UE and the U2N Relay UE perform a discovery procedure and can perform a PC5 RRC connection based on this.

[0134] In step 2, the remote UE may send an RRC Setup request message (also known as RRCReestablishmentRequest, or RRCResumeRequest) to the gNB via the PC5 RRC connected Relay UE.

[0135] Based on this, PC5 and Uu RLC channels for SRB1 can be prepared in step 3. In this embodiment, it is proposed that the relay UE transmits the SI information acquired from the gNB through the PC5 interface.

[0136] In step 4, the gNB may send an RRC Setup Complete message to the remote UE via the Relay UE based on the information received in step 2.

[0137] Afterwards, in step 5, settings related to security mode can be performed, and in step 6, RRC reconfiguration procedures can be performed to suit the SRB2 / DRBs to the U2N Relay situation.

[0138]

[0139] Meanwhile, in another embodiment of the present invention, the UEs as described above belong to one UE group, and a UE that updates SI by itself through a gNB corresponds to a group head, and a UE that shares it may be utilized in a form corresponding to a UE supported by the group head.

[0140] In another embodiment of the present invention, assuming that the above-described NTN is located on a low-orbit satellite, a first UE that directly acquires SI and shares it with another UE through a sidelink can be operated so as to be determined based on flight path information of the low-orbit satellite.

[0141]

[0142] Figure 11 illustrates a wireless device to which the present technology can be applied.

[0143] Referring to FIG. 11, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, the first wireless device (100) and the second wireless device (200) may correspond to UE 1 and UE 2 of FIG. 5, respectively, or may correspond to UE1 and gNB of FIG. 5.

[0144] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0145] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including commands for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0146] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0147] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0148] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0149] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0150]

[0151] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can utilize the individual components described in the above-described embodiments in combination with each other.

[0152] Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0153] The SI information sharing method and device therefor through sidelink according to the embodiments of the present invention as described above are suitable for use in the NTN application environment discussed in 3GPP, but as described above, they can also be widely used in various situations where individual acquisition of SI information is difficult in communication methods other than 3GPP.

Claims

1. In a method for a first user equipment (UE) to perform communication with a network in a mobile communication system, The first user device receives a MIB (Master Information Block) among SI (System Information) from a specific cell of the network; Receive SIB (System Information Block) 1 based on the above MIB information; and A method for communicating with a network, comprising: transmitting the SI to a second user device via a sidelink when it is confirmed that the specific cell is a NTN (Non-Terrestrial Network) cell through the information of the SIB 1.

2. In paragraph 1, The SI transmitted to the second user device includes SIB 19, which is essential for NTN access, A method for communicating with a network, wherein the second user device transmits a message requesting the SIB 19 to the first user device via the sidelink when the specific cell is an NTN cell and does not receive the SIB 19 from the sidelink.

3. In paragraph 1, The SI transmitted to the second user device includes SIB 19, which is essential for NTN access, The second user device, if the specific cell is an NTN cell and receives SIB 19 from the sidelink, By driving the first timer having the NTN uplink synchronization valid period from the time unit indicated by the epoch time (epochTime), A method of communicating with a network, comprising transmitting a SIB 19 request message to the first user device via a sidelink if the SIB 19 is not re-received before the first timer expires.

4. In paragraph 2, Transmitting a message requesting the above SIB 19 over the sidelink, A method of communicating with a network, transmitting only when the RSRP (Reference Signal Received Power) or RSRQ (Reference Signal Received Quality) of the NTN cell measured by the second user device is below a predetermined standard.

5. In paragraph 2, Transmitting a message requesting the above SIB 19 over the sidelink, A method of communicating with a network, wherein the second user device transmits when the second user device operates in a power saving mode or to reduce power consumption.

6. In paragraph 1, Transmitting the above SI to the second user device via the side link, A method of communicating with a network, wherein only SI for NTN cells whose RSRP or RSRQ measured through one or more of SSB (Synchronization Signal Block) or CSI-RS (Channel State Information - Reference Signal) received from multiple NTN cells is higher than a predetermined standard is transmitted.

7. In paragraph 1, The first user device and the second user device are located in platooning vehicles, A method for communicating with a network, wherein the first user device is located in a Leading Vehicle (LV) and the second user device is located in a Following Vehicle (FV).

8. In paragraph 1, The above NTN is located on a low-orbit satellite, A method for communicating with a network, wherein the first user device is determined based on movement path information of the low-orbit satellite.

9. In paragraph 1, The above first user device is a U2N (User-to-Network) relay user device, A method for communicating with a network, wherein the second user device corresponds to a remote user device.

10. In paragraph 1, The above first user device and the above second user device belong to one user device group, A method for communicating with a network, wherein the first user device corresponds to a group head user device.

11. In a method for a network to perform communication with a first user equipment (UE) in a mobile communication system, Transmitting MIB (Master Information Block) of SI (System Information) through a specific cell of the network to the first user device; and Including transmitting SIB (System Information Block) 1 to the first user device based on the above MIB information, A communication method of a network, wherein the network indicates that the specific cell is a NTN (Non-Terrestrial Network) cell through information of the SIB 1, and instructs the first user device to share the SI with the second user device through a sidelink.

12. In paragraph 11, The SI transmitted to the second user device includes SIB 19, which is essential for NTN access, The above SIB 19 is a communication method of a network, which includes an NTN configuration (NTN-Config) information element.

13. In paragraph 12, A method of communication in a network, wherein the instruction to share the above SI via a sidelink is performed via a specific field of the NTN configuration (NTN-Config) information element.

14. In paragraph 11, The first user device and the second user device are located in platooning vehicles, A communication method of a network, wherein the first user device is located in a Leading Vehicle (LV) and the second user device is located in a Following Vehicle (FV).

15. In paragraph 11, The above NTN is located on a low-orbit satellite, A communication method of a network, wherein the network determines the first user device based on the movement path information of the low-orbit satellite.

16. In paragraph 11, The above first user device is a U2N (User-to-Network) relay user device, A method of communication in a network, wherein the second user device corresponds to a remote user device.

17. In paragraph 11, The above first user device and the above second user device belong to one user device group, A network communication method, wherein the first user device corresponds to a group head user device.

18. In a device that operates as a first user equipment (UE) that performs network and communication in a mobile communication system, at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, The first user device receives a MIB (Master Information Block) among SI (System Information) from a specific cell of the network; Receive SIB (System Information Block) 1 based on the above MIB information; and A user equipment device, comprising: a device for transmitting the SI to a second user equipment via a sidelink when it is determined through the information of the SIB 1 that the specific cell is a NTN (Non-Terrestrial Network) cell.

19. In a network that performs communication with a first user equipment (UE) in a mobile communication system, at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Transmitting MIB (Master Information Block) of SI (System Information) through a specific cell of the network to the first user device; and Including transmitting SIB (System Information Block) 1 to the first user device based on the above MIB information, A network in which the network indicates that the specific cell is a Non-Terrestrial Network (NTN) cell through information of the SIB 1, and instructs the first user device to share the SI with the second user device via a sidelink.

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