KR20240044333A - Methods for processing communication using multi-path and apparatuses thereof - Google Patents

Abstract

The present disclosure relates to a technology in which a remote terminal connected to a base station through a relay terminal transmits and receives data through a direct path and an indirect path. In a method for a remote terminal to perform communication through multiple paths, the direct path and the indirect path from the base station are disclosed. Receiving configuration information for configuring multiple paths including; configuring multiple paths by applying the configuration information; and transmitting an RRC message when a radio link failure is detected in at least one of the multiple paths. A method and device comprising:

Description

Method and device for processing communication using multiple paths {METHODS FOR PROCESSING COMMUNICATION USING MULTI-PATH AND APPARATUSES THEREOF}

This disclosure relates to a technology in which a remote terminal connected to a base station through a relay terminal transmits and receives data through a direct path and an indirect path.

Sidelink communication, which can be used for inter-vehicle communication, is being discussed in 3GPP and technology is being developed. Sidelink (SL) refers to a communication method that establishes a direct link between terminals (User Equipment, UE) and directly exchanges voice or data between terminals without going through a base station (BS). SL is being considered as a way to solve the burden on base stations due to rapidly increasing data traffic.

Meanwhile, in wireless communication technology, relay technology that provides additional hops during the terminal's connection to the base station is provided. Conventionally, relay technology has been applied between terminals and base stations, and technologies for applying relay technology to sidelink communications are also being researched.

The sidelink relay can support the UE to Network relay function that provides connection to a UE to Network (U2N) remote terminal. L2 and L3 U2N relay structures can be supported. The U2N relay terminal must be in RRC connection state to perform relaying of unicast data.

In the prior art, for an L2 U2N remote terminal in the RRC idle/inactive state, the cell selection/reselection procedure and the relay selection/reselection procedure can operate independently. If suitable cells and suitable U2N relay terminals are available, it was up to the terminal implementation to select one cell or one U2N relay terminal. Accordingly, in order for the U2N remote terminal to transmit data, a direct path is taken from the corresponding cell through the base station and the Uu wireless interface (Direct Path: a type of UE-to-Network transmission path, where data is transmitted between a UE and the network without sidelink relaying .) and an indirect path through the corresponding U2N relay terminal (Indirect Path: a type of UE-to-Network transmission path, where data is forwarded via a U2N Relay UE between a U2N Remote UE and the This could be achieved by selecting one of RRC/SRB/DRB connections through network.).

Therefore, problems with lower throughput and wireless reliability may occur compared to using multiple transmission paths.

Against the above-mentioned background, the present disclosure seeks to provide a technology in which a remote terminal connected to a base station through a relay terminal transmits and receives data through a direct path and an indirect path.

In one aspect, the present embodiments are a method for a remote terminal to perform communication through multiple paths, including receiving configuration information for configuring multiple paths including a direct path and an indirect path from a base station and applying the configuration information. Thus, it is possible to provide a method including configuring multiple paths and transmitting an RRC message when a radio link failure is detected in at least one path among the plurality of paths.

In another aspect, the present embodiments are a method for a base station to control communication through multiple paths of a remote terminal, including the steps of transmitting an RRC reconfiguration message for indirect path configuration to a relay terminal providing a connection to the remote terminal and directly Transmitting configuration information for configuring a plurality of paths including a path and an indirect path to a remote terminal, and receiving an RRC message when a radio link failure is detected in at least one of the plurality of paths in the remote terminal. A method including can be provided.

In another aspect, the present embodiments apply the configuration information and a receiving unit that receives configuration information for configuring multiple paths including a direct path and an indirect path from a base station in a remote terminal that performs communication through multiple paths. A remote terminal device including a control unit configuring multiple paths and a transmitter that transmits an RRC message when a wireless link failure is detected in at least one of the multiple paths can be provided.

In another aspect, these embodiments transmit an RRC reconfiguration message for indirect path configuration to a relay terminal that provides connection to the remote terminal in the base station that controls communication through multiple paths of the remote terminal, and configure the direct path and Includes a transmitter that transmits configuration information for configuring multiple paths, including indirect paths, to the remote terminal, and a receiver that receives an RRC message when a wireless link failure is detected in at least one of the multiple paths in the remote terminal. A base station device can be provided.

In light of the above-described background, the present disclosure can provide a technology in which a remote terminal connected to a base station through a relay terminal transmits and receives data through a direct path and an indirect path.

Figure 1 is a diagram briefly illustrating the structure of an NR wireless communication system to which this embodiment can be applied.
Figure 2 is a diagram for explaining the frame structure in an NR system to which this embodiment can be applied.
FIG. 3 is a diagram illustrating a resource grid supported by wireless access technology to which this embodiment can be applied.
Figure 4 is a diagram for explaining the bandwidth part supported by the wireless access technology to which this embodiment can be applied.
Figure 5 is a diagram illustrating a synchronization signal block in a wireless access technology to which this embodiment can be applied.
Figure 6 is a diagram for explaining a random access procedure in wireless access technology to which this embodiment can be applied.
Figure 7 is a diagram to explain CORESET.
FIG. 8 is a diagram illustrating the control plane protocol structure for an L2 UE-to-Network relay according to an embodiment.
Figure 9 is a diagram for explaining remote terminal operations according to one embodiment.
Figure 10 is a diagram for explaining the operation of a base station according to an embodiment.
FIG. 11 is a diagram to explain an example of a split radio bearer/SRB/DRB configuration through multiple paths.
Figure 12 is a diagram showing the configuration of a remote terminal according to one embodiment.
Figure 13 is a diagram showing the configuration of a base station according to one embodiment.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to illustrative drawings. In adding reference numerals to components in each drawing, the same components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present technical idea, the detailed description may be omitted. When “comprises,” “has,” “consists of,” etc. mentioned in the specification are used, other parts may be added unless “only” is used. When a component is expressed in the singular, it can also include the plural, unless specifically stated otherwise.

Additionally, in describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being “connected,” “coupled,” or “connected,” the two or more components are directly “connected,” “coupled,” or “connected.” ", but it should be understood that two or more components and other components may be further "interposed" and "connected," "combined," or "connected." Here, other components may be included in one or more of two or more components that are “connected,” “coupled,” or “connected” to each other.

In the description of temporal flow relationships related to components, operation methods, production methods, etc., for example, temporal precedence relationships such as “after”, “after”, “after”, “before”, etc. Or, when a sequential relationship is described, non-continuous cases may be included unless “immediately” or “directly” is used.

On the other hand, when a numerical value or corresponding information (e.g., level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or corresponding information is related to various factors (e.g., process factors, internal or external shocks, It can be interpreted as including the error range that may occur due to noise, etc.).

The wireless communication system in this specification refers to a system for providing various communication services such as voice and data packets using wireless resources, and may include a terminal, a base station, or a core network.

The present embodiments disclosed below can be applied to wireless communication systems using various wireless access technologies. For example, the present embodiments include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). Alternatively, it can be applied to a variety of different wireless access technologies such as NOMA (non-orthogonal multiple access). In addition, wireless access technology not only refers to a specific access technology, but also refers to communication technology for each generation established by various communication consultative organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA can be implemented as a wireless technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented with wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), etc. IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of the universal mobile telecommunications system (UMTS). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC- in the uplink. FDMA is adopted. In this way, the present embodiments can be applied to wireless access technologies currently disclosed or commercialized, and can also be applied to wireless access technologies currently under development or to be developed in the future.

Meanwhile, the terminal in this specification is a comprehensive concept meaning a device including a wireless communication module that communicates with a base station in a wireless communication system, and is used in WCDMA, LTE, NR, HSPA, and IMT-2020 (5G or New Radio), etc. It should be interpreted as a concept that includes not only UE (User Equipment), but also MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), and wireless devices in GSM. In addition, a terminal may be a user portable device such as a smart phone depending on the type of use, and in a V2X communication system, it may mean a vehicle, a device including a wireless communication module within the vehicle, etc. Additionally, in the case of a machine type communication system, it may mean an MTC terminal, M2M terminal, URLLC terminal, etc. equipped with a communication module to perform machine type communication.

The base station or cell in this specification refers to an end point that communicates with a terminal in terms of a network, and includes Node-B (Node-B), evolved Node-B (eNB), gNode-B (gNB), Low Power Node (LPN), Sector, site, various types of antennas, BTS (Base Transceiver System), access point, point (e.g. transmission point, reception point, transmission/reception point), relay node ), mega cell, macro cell, micro cell, pico cell, femto cell, RRH (Remote Radio Head), RU (Radio Unit), and small cell. Additionally, a cell may mean including a bandwidth part (BWP) in the frequency domain. For example, a serving cell may mean the UE's Activation BWP.

Since the various cells listed above have a base station that controls one or more cells, base station can be interpreted in two ways. 1) It may be the device itself that provides mega cells, macro cells, micro cells, pico cells, femto cells, and small cells in relation to the wireless area, or 2) it may indicate the wireless area itself. In 1), all devices providing a predetermined wireless area are controlled by the same entity or all devices that interact to collaboratively configure the wireless area are directed to the base station. Depending on how the wireless area is configured, a point, transmission/reception point, transmission point, reception point, etc. become an example of a base station. In 2), the wireless area itself where signals are received or transmitted from the user terminal's perspective or the neighboring base station's perspective may be indicated to the base station.

In this specification, a cell may mean coverage of a signal transmitted from a transmission/reception point, a component carrier having coverage of a signal transmitted from a transmission point or transmission/reception point, or the transmission/reception point itself. You can.

Uplink (UL, or uplink) refers to a method of transmitting and receiving data from a terminal to a base station, and downlink (Downlink, DL, or downlink) refers to a method of transmitting and receiving data from a base station to a terminal. do. Downlink may refer to communication or a communication path from multiple transmission/reception points to a terminal, and uplink may refer to communication or a communication path from a terminal to multiple transmission/reception points. At this time, in the downlink, the transmitter may be part of a multiple transmission/reception point, and the receiver may be part of the terminal. Additionally, in the uplink, a transmitter may be part of a terminal, and a receiver may be part of a multiple transmission/reception point.

Uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control CHannel), and PDSCH (Physical Downlink Shared CHannel), PUSCH (Physical Uplink Shared CHannel), etc. Data is transmitted and received by configuring the same data channel. Hereinafter, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH and PDSCH may be expressed as 'transmitting and receiving PUCCH, PUSCH, PDCCH and PDSCH'. do.

For clarity of explanation, the technical idea below is mainly described in the 3GPP LTE/LTE-A/NR (New RAT) communication system, but the technical features are not limited to the corresponding communication system.

Following research on 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of ITU-R's next-generation wireless access technology. Specifically, 3GPP develops LTE-A pro, which is a 5G communication technology that improves LTE-Advanced technology to meet the requirements of ITU-R, and a new NR communication technology that is separate from 4G communication technology. Both LTE-A pro and NR refer to 5G communication technology, and hereinafter, 5G communication technology will be explained focusing on NR in cases where a specific communication technology is not specified.

The operating scenario in NR defines a variety of operating scenarios by adding consideration of satellites, automobiles, and new verticals to the existing 4G LTE scenario, and in terms of service, the eMBB (Enhanced Mobile Broadband) scenario has a high terminal density but is wide. It is deployed in a wide range of applications, supporting mMTC (Massive Machine Communication) scenarios that require low data rates and asynchronous connections, and URLLC (Ultra Reliability and Low Latency) scenarios that require high responsiveness and reliability and can support high-speed mobility. .

To satisfy this scenario, NR is launching a wireless communication system with new waveform and frame structure technology, low latency technology, ultra-high frequency band (mmWave) support technology, and forward compatible technology. In particular, the NR system proposes various technical changes in terms of flexibility to provide forward compatibility. The main technical features of NR are explained below with reference to the drawings.

<NR system general>

Figure 1 is a diagram briefly illustrating the structure of an NR system to which this embodiment can be applied.

Referring to Figure 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN parts, and NG-RAN controls the user plane (SDAP/PDCP/RLC/MAC/PHY) and UE (User Equipment). It consists of gNB and ng-eNB providing flat (RRC) protocol termination. gNB interconnection or gNB and ng-eNB are interconnected through Xn interface. gNB and ng-eNB are each connected to 5GC through the NG interface. 5GC may be composed of an Access and Mobility Management Function (AMF), which is responsible for the control plane such as terminal access and mobility control functions, and a User Plane Function (UPF), which is responsible for controlling user data. NR includes support for both the frequency band below 6 GHz (FR1, Frequency Range 1) and the frequency band above 6 GHz (FR2, Frequency Range 2).

gNB refers to a base station that provides NR user plane and control plane protocol termination to the terminal, and ng-eNB refers to a base station that provides E-UTRA user plane and control plane protocol termination to the terminal. The base station described in this specification should be understood to encompass gNB and ng-eNB, and may be used to refer to gNB or ng-eNB separately, if necessary.

<NR wave form, numerology and frame structure>

In NR, the CP-OFDM wave form using a cyclic prefix is used for downlink transmission, and CP-OFDM or DFT-s-OFDM is used for uplink transmission. OFDM technology is easy to combine with MIMO (Multiple Input Multiple Output) and has the advantage of being able to use a low-complexity receiver with high frequency efficiency.

Meanwhile, in NR, the requirements for data rate, delay rate, coverage, etc. are different for each of the three scenarios described above, so it is necessary to efficiently satisfy the requirements for each scenario through the frequency band that constitutes an arbitrary NR system. . To this end, a technology for efficiently multiplexing wireless resources based on a plurality of different numerologies has been proposed.

Specifically, the NR transmission numerology is determined based on sub-carrier spacing and CP (Cyclic prefix), and as shown in Table 1 below, the μ value is used as an exponent value of 2 based on 15 kHz, resulting in an exponential is changed to

μ Subcarrier spacing Cyclic prefix Supported for data Supported for synchronization 0 15 Normal Yes Yes One 30 Normal Yes Yes 2 60 Normal, Extended Yes No 3 120 Normal Yes Yes 4 240 Normal No Yes

As shown in Table 1 above, NR's numerology can be divided into five types depending on the subcarrier spacing. This is different from the subcarrier spacing of LTE, one of the 4G communication technologies, which is fixed at 15kHz. Specifically, the subcarrier intervals used for data transmission in NR are 15, 30, 60, and 120 kHz, and the subcarrier intervals used for synchronization signal transmission are 15, 30, 120, and 240 kHz. Additionally, the extended CP applies only to the 60kHz subcarrier spacing. Meanwhile, the frame structure in NR is defined as a frame with a length of 10ms consisting of 10 subframes with the same length of 1ms. One frame can be divided into half-frames of 5ms, and each half-frame contains 5 subframes. In the case of 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols.

Figure 2 is a diagram for explaining the frame structure in an NR system to which this embodiment can be applied.

Referring to FIG. 2, a slot is fixedly composed of 14 OFDM symbols in the case of normal CP, but the length of the slot in the time domain may vary depending on the subcarrier spacing. For example, in the case of numerology with a 15 kHz subcarrier spacing, a slot is 1 ms long and has the same length as a subframe. In contrast, in the case of numerology with a 30 kHz subcarrier spacing, a slot consists of 14 OFDM symbols, but two slots can be included in one subframe with a length of 0.5 ms. That is, subframes and frames are defined with a fixed time length, and slots are defined by the number of symbols, so the time length may vary depending on the subcarrier interval.

Meanwhile, NR defines the basic unit of scheduling as a slot, and also introduces a mini-slot (or sub-slot or non-slot based schedule) to reduce transmission delay in the wireless section. When a wide subcarrier spacing is used, the length of one slot is shortened in inverse proportion, so transmission delay in the wireless section can be reduced. Mini-slots (or sub-slots) are designed to efficiently support URLLC scenarios and can be scheduled in units of 2, 4, or 7 symbols.

Additionally, unlike LTE, NR defines uplink and downlink resource allocation at the symbol level within one slot. In order to reduce HARQ delay, a slot structure that can transmit HARQ ACK/NACK directly within the transmission slot has been defined, and this slot structure is described as a self-contained structure.

NR is designed to support a total of 256 slot formats, of which 62 slot formats are used in 3GPP Rel-15. In addition, it supports a common frame structure that forms an FDD or TDD frame through a combination of various slots. For example, a slot structure in which all slot symbols are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink symbols and uplink symbols are combined are supported. Additionally, NR supports scheduling data transmission distributed over one or more slots. Therefore, the base station can use a slot format indicator (SFI) to inform the terminal whether the slot is a downlink slot, an uplink slot, or a flexible slot. The base station can indicate the slot format by indicating the index of the table configured through UE-specific RRC signaling using SFI, and can indicate it dynamically through DCI (Downlink Control Information) or statically or through RRC. It can also be indicated semi-statically.

<NR physical resources>

Regarding physical resources in NR, antenna port, resource grid, resource element, resource block, bandwidth part, etc. are considered. do.

An antenna port is defined so that a channel carrying a symbol on the antenna port can be inferred from a channel carrying another symbol on the same antenna port. If the large-scale properties of the channel carrying the symbols on one antenna port can be inferred from the channel carrying the symbols on the other antenna port, the two antenna ports are quasi co-located or QC/QCL. It can be said that they are in a quasi co-location relationship. Here, the wide range characteristics include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

FIG. 3 is a diagram illustrating a resource grid supported by wireless access technology to which this embodiment can be applied.

Referring to FIG. 3, since NR supports multiple numerology on the same carrier, a resource grid may exist for each numerology. Additionally, resource grids may exist depending on antenna ports, subcarrier spacing, and transmission direction.

A resource block consists of 12 subcarriers and is defined only in the frequency domain. Additionally, a resource element consists of one OFDM symbol and one subcarrier. Therefore, as shown in FIG. 3, the size of one resource block may vary depending on the subcarrier spacing. Additionally, NR defines "Point A", which serves as a common reference point for the resource block grid, common resource blocks, virtual resource blocks, etc.

Figure 4 is a diagram for explaining the bandwidth part supported by the wireless access technology to which this embodiment can be applied.

In NR, unlike LTE, where the carrier bandwidth is fixed at 20Mhz, the maximum carrier bandwidth is set from 50Mhz to 400Mhz for each subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in NR, the terminal can use a designated bandwidth part (BWP) within the carrier bandwidth as shown in FIG. 4. Additionally, the bandwidth part is linked to one numerology and consists of a subset of consecutive common resource blocks, and can be activated dynamically over time. The terminal is configured with up to four bandwidth parts for each uplink and downlink, and data is transmitted and received using the bandwidth parts activated at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, to prevent unnecessary frequency re-tunning between downlink and uplink operations. For this purpose, the bandwidth parts of the downlink and uplink are set in pairs so that they can share the center frequency.

<NR initial access>

In NR, the terminal performs cell search and random access procedures to connect to the base station and perform communication.

Cell search is a procedure in which the terminal synchronizes to the cell of the base station, obtains a physical layer cell ID, and obtains system information using a synchronization signal block (SSB) transmitted by the base station.

Figure 5 is a diagram illustrating a synchronization signal block in a wireless access technology to which this embodiment can be applied.

Referring to FIG. 5, the SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), each occupying 1 symbol and 127 subcarriers, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

The terminal monitors the SSB in the time and frequency domains and receives the SSB.

SSB can be transmitted up to 64 times in 5ms. Multiple SSBs are transmitted through different transmission beams within 5ms, and the terminal performs detection assuming that SSBs are transmitted every 20ms period based on one specific beam used for transmission. The number of beams that can be used for SSB transmission within 5ms time can increase as the frequency band becomes higher. For example, up to 4 different SSB beams can be transmitted under 3 GHz, up to 8 different beams can be used in the frequency band from 3 to 6 GHz, and up to 64 different beams can be used in the frequency band above 6 GHz.

Two SSBs are included in one slot, and the start symbol and number of repetitions within the slot are determined according to the subcarrier spacing as follows.

Meanwhile, unlike SS in conventional LTE, SSB is not transmitted at the center frequency of the carrier bandwidth. In other words, SSBs can be transmitted even in places other than the center of the system band, and when broadband operation is supported, multiple SSBs can be transmitted in the frequency domain. Accordingly, the terminal monitors the SSB using a synchronization raster, which is a candidate frequency location for monitoring the SSB. The carrier raster and synchronization raster, which are the center frequency location information of the channel for initial access, have been newly defined in NR, and the synchronization raster has a wider frequency interval than the carrier raster, supporting fast SSB search of the terminal. You can.

The UE can obtain the MIB through the PBCH of the SSB. MIB (Master Information Block) contains the minimum information required for the terminal to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH includes information about the location of the first DM-RS symbol in the time domain, information for the terminal to monitor SIB1 (e.g., SIB1 numerology information, information related to SIB1 CORESET, search space information, PDCCH (related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB within the carrier is transmitted through SIB1), etc. Here, the SIB1 numerology information is equally applied to some messages used in the random access procedure for accessing the base station after the terminal completes the cell search procedure. For example, numerology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

The above-mentioned RMSI may mean SIB1 (System Information Block 1), and SIB1 is broadcast periodically (ex, 160ms) in the cell. SIB1 contains information necessary for the terminal to perform the initial random access procedure and is transmitted periodically through PDSCH. In order for the terminal to receive SIB1, it must receive numerology information used for SIB1 transmission and CORESET (Control Resource Set) information used for scheduling SIB1 through the PBCH. The UE uses SI-RNTI in CORESET to check scheduling information for SIB1 and acquires SIB1 on the PDSCH according to the scheduling information. Except for SIB1, the remaining SIBs may be transmitted periodically or according to the request of the terminal.

Figure 6 is a diagram for explaining a random access procedure in wireless access technology to which this embodiment can be applied.

Referring to FIG. 6, when cell search is completed, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted through PRACH. Specifically, the random access preamble is transmitted to the base station through PRACH, which consists of continuous radio resources in a specific slot that is repeated periodically. Generally, when a UE initially accesses a cell, a contention-based random access procedure is performed, and when random access is performed for beam failure recovery (BFR), a non-contention-based random access procedure is performed.

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), UL Grant (uplink radio resource), temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and TAC (Time Alignment Command). Since one random access response may include random access response information for one or more terminals, the random access preamble identifier may be included to indicate to which terminal the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. TAC may be included as information for the terminal to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, RA-RNTI (Random Access - Radio Network Temporary Identifier).

The terminal that has received a valid random access response processes the information included in the random access response and performs scheduled transmission to the base station. For example, the terminal applies TAC and stores temporary C-RNTI. Additionally, using the UL Grant, data stored in the terminal's buffer or newly generated data is transmitted to the base station. In this case, information that can identify the terminal must be included.

Finally, the terminal receives a downlink message to resolve contention.

<NR CORESET>

The downlink control channel in NR is transmitted in CORESET (Control Resource Set) with a length of 1 to 3 symbols, and transmits uplink/downlink scheduling information, SFI (Slot format Index), and TPC (Transmit Power Control) information. .

In this way, in order to secure the flexibility of the system, NR introduced the CORESET concept. CORESET (Control Resource Set) refers to time-frequency resources for downlink control signals. The terminal may decode the control channel candidate using one or more search spaces in the CORESET time-frequency resource. QCL (Quasi CoLocation) assumptions were set for each CORESET, and this is used for the purpose of informing the characteristics of the analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay, which are the characteristics assumed by the conventional QCL.

Figure 7 is a diagram to explain CORESET.

Referring to FIG. 7, CORESET may exist in various forms within one slot and within the carrier bandwidth, and in the time domain, CORESET may be composed of up to three OFDM symbols. Additionally, CORESET is defined as a multiple of 6 resource blocks from the frequency domain to the carrier bandwidth.

The first CORESET is directed through the MIB as part of the initial bandwidth part configuration to enable it to receive additional configuration and system information from the network. After establishing a connection with the base station, the terminal can receive and configure one or more CORESET information through RRC signaling.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, or various messages related to NR (New Radio) can be interpreted in a variety of meanings that may be used in the past or present, or may be used in the future.

side link relay

Sidelink relay was introduced to support the UE to Network relay function that provides connection to a UE to Network (U2N) remote terminal. L2 and L3 U2N relay structures can be supported. The U2N relay terminal must be in RRC connection state to perform relaying of unicast data.

The following RRC state combinations are supported for L2 U2N relay operation.

- The U2N relay terminal and U2N remote terminal must be in an RRC connection state to transmit/receive relayed unicast data.

- As long as all U2N remote terminals connected to the U2N relay terminal are in RRC inactive or RRC idle, the U2N relay terminal can be in RRC idle, RRC inactive, or RRC connected state.

FIG. 8 is a diagram illustrating the control plane protocol structure for an L2 UE-to-Network relay according to an embodiment.

Referring to Figure 8, a remote terminal can be connected to the base station through a relay terminal. The remote terminal and relay terminal can be connected to physical, MAC, and RLC channels through the PC5 interface. The relay terminal can be connected to the base station through the Uu interface. Additionally, the remote terminal and the base station may be connected to the Uu interface in the PDCP and RRC layers.

In the prior art, for an L2 U2N remote terminal in the RRC idle/inactive state, the cell selection/reselection procedure and the relay selection/reselection procedure can operate independently. If suitable cells and suitable U2N relay terminals are available, it was up to the terminal implementation to select one cell or one U2N relay terminal. Accordingly, in order for the U2N remote terminal to transmit data, a direct path is taken from the corresponding cell through the base station and the Uu wireless interface (Direct Path: a type of UE-to-Network transmission path, where data is transmitted between a UE and the network without sidelink relaying .) and an indirect path through the corresponding U2N relay terminal (Indirect Path: a type of UE-to-Network transmission path, where data is forwarded via a U2N Relay UE between a U2N Remote UE and the network.) could be achieved by selecting one of RRC/SRB/DRB connections. Therefore, throughput and wireless reliability could be lower compared to using multiple transmission paths. However, no specific method was provided for how the remote terminal can simultaneously use the direct path and indirect path.

In conventional sidelink relay technology, remote terminals can transmit and receive data by selecting either a direct path or an indirect path, which can reduce throughput and wireless reliability. However, no specific technology was provided on how the remote terminal uses the direct path and indirect path simultaneously.

The present disclosure, designed to solve the above problems, proposes a method and device for a remote terminal to transmit and receive data using a direct path and an indirect path simultaneously. In addition, we would like to suggest a handling method in case a wireless link failure occurs in this situation.

Hereinafter, the 5GS/NR technology-based data transmission and reception method and wireless failure handling method will be described. However, this is for convenience of explanation, and the present embodiments can be applied to any system/wireless access technology (e.g. LTE, 6G). The embodiment described in this disclosure includes the contents of information elements and operations specified in the NR/5GS standard (e.g. TS 38.321, the MAC standard, TS 38.331, etc., the NR RRC standard). Even if the definition of the corresponding information element and the related terminal operation content are not included in this specification, the corresponding content specified in the standard specification, which is a known technology, can be combined and included in this embodiment.

The embodiment provided below can be applied to sidelink communication between NR terminals and NR terminals through an NR/LTE base station. The embodiment provided below may be applied to sidelink communication between an NR terminal and an LTE terminal (or any inter-RAT terminal) through an NR/LTE base station. The embodiments provided below may be applied to sidelink communication between LTE terminals and LTE terminals through an NR/LTE base station. The embodiment provided below may be applied to sidelink communication between LTE terminals through an LTE base station (or any inter-RAT base station). That is, these embodiments can be applied regardless of the sidelink communication configuration type.

Meanwhile, any function described below is defined as an individual terminal capability (UE radio capability or UE Core network capability) and is transmitted by the terminal to the base station/core network entity (e.g. AMF/SMF)/counterpart terminal through corresponding signaling. can be sent to Alternatively, arbitrary functions may be combined/combined, defined as the terminal capability, and transmitted by the terminal to the base station/core network entity/counterpart through corresponding signaling. The base station may transmit/instruct to the terminal through an RRC message information indicating permission/support/configuration of the function/function combination for any function or combination of functions described below. For example, the RRC message may be indicated to the terminal before or after configuration/application of the function/function combination, or simultaneously with configuration/application of the function/function combination. Alternatively, the corresponding RRC message may be broadcast through system information. Alternatively, the corresponding indication information may be indicated to the terminal through a dedicated RRC message. Alternatively, the corresponding indication information may be indicated to the terminal through the sidelink BCCH/DCCH.

The functions described below can be performed individually and independently. It is obvious that the functions described below can be implemented in any combination/combination, and this is also included in the scope of this embodiment. For example, more than one function may be applied simultaneously.

A remote terminal in this specification may refer to a terminal that is connected to a base station through a relay terminal and performs communication. A relay terminal refers to a terminal that performs the function of linking a remote terminal to a base station. A remote terminal can be linked to the base station through a direct path and an indirect path. Therefore, in this specification, the terms remote terminal and relay terminal are used to mean a terminal that provides the corresponding function, and are not limited thereto. Below, the operations of the remote terminal and base station according to this embodiment will be described with reference to the drawings.

Figure 9 is a diagram for explaining remote terminal operations according to one embodiment.

Referring to FIG. 9, a remote terminal that performs communication through multiple paths may receive configuration information for configuring multiple paths including a direct path and an indirect path from the base station (S910).

For example, the remote terminal may receive configuration information for configuring multiple paths including a direct path to the base station and an indirect path through a relay terminal. As an example, configuration information may be received from a base station through higher layer signaling. For example, configuration information may be received through an RRC message. As another example, configuration information may be received through a relay terminal.

Configuration information includes direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, and separate signaling. It may include at least one of radio bearer (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. For example, the configuration information may include additional direct path configuration information for additionally configuring a direct path to the remote terminal. Additionally, the configuration information may include indirect path additional configuration information for additionally configuring an indirect path to the remote terminal. Additionally, the configuration information may include direct path RLC bearer configuration information and/or indirect path RLC bearer configuration information for configuring a path for each bearer. Alternatively, the configuration information may include bearer mapping configuration information for mapping bearers and paths. In addition, the configuration information may include at least one radio bearer configuration information among direct path radio bearer configuration information, indirect path radio bearer configuration information, split SRB configuration information, and split DRB configuration information. The configuration information may include L2 relay terminal identification information connected to the remote terminal.

The remote terminal can perform the step of configuring multiple paths by applying configuration information (S920).

For example, when a remote terminal receives configuration information from a base station, it can configure multiple paths to the terminal based on the configuration information. As an example, the remote terminal may configure the primary path of the split signaling radio bearer (Split SRB) as a direct path. As another example, the remote terminal may configure an indirect path by establishing a PC5 RRC connection with the relay terminal.

The remote terminal can be configured by adding a direct path and/or an indirect path using information included in the configuration information. Alternatively, the remote terminal may configure a radio bearer indicated by configuration information in the terminal and control communication to be performed using a direct path and/or an indirect path.

The remote terminal can communicate with the base station through multiple configured paths. However, limitations in communication may occur due to various factors during communication. For example, a communication failure situation may be detected, such as a wireless link failure.

When a wireless link failure is detected in at least one of the plurality of paths, the remote terminal may transmit an RRC message (S930).

For example, the remote terminal can monitor whether a wireless link failure occurs for multiple paths. If a wireless link failure is detected in one or more of the plurality of paths, the remote terminal can transmit information about the occurrence of the failure through an RRC message.

For example, if the path on which a wireless link failure is detected is a direct path, the RRC message may be transmitted as path failure reporting through an indirect path.

As another example, if the path where a wireless link failure is detected is an indirect path, the RRC message may be transmitted as path failure reporting through a direct path.

For example, a wireless link failure detected on the indirect path may be a notification due to a sidelink failure or a wireless link failure between the relay terminal and the base station on the indirect path. That is, when a sidelink failure is detected, a problem may occur in communication between the remote terminal and the relay terminal, and a wireless link failure may be detected on the indirect path. Alternatively, if a wireless link failure occurs between the relay terminal and the base station, the remote terminal can detect the wireless link failure on the indirect path. In this case, a wireless link failure between the relay terminal and the base station may be notified.

As another example, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal may perform a cell selection or relay selection operation according to the RRC reset procedure. Additionally, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal can transmit an RRC reset request message to the base station. The cell selection or relay selection operation may be performed before transmitting the RRC reset request message, or may be performed after transmitting the RRC reset request message. Alternatively, transmission of the RRC reset request message may be performed as one of cell selection or relay selection operations.

Meanwhile, the RRC message transmitted for path failure reporting may include information on the cause of failure. Alternatively, the RRC message may include information about the radio bearer for which a radio link failure was detected, failure type information, etc.

Meanwhile, the base station may further transmit an RRC reconfiguration message for indirect path configuration to the relay terminal that provides connectivity between the remote terminal and the base station before step S910.

Through the above operation, a remote terminal that communicates through a plurality of different paths such as direct path and indirect path can prevent deterioration of the communication situation by taking quick action when a wireless link failure is detected.

Figure 10 is a diagram for explaining the operation of a base station according to an embodiment.

Referring to FIG. 10, the base station controlling communication through multiple paths of the remote terminal may perform the step of transmitting an RRC reconfiguration message for indirect path configuration to the relay terminal providing connection to the remote terminal (S1010). .

For example, the base station may transmit an RRC reconfiguration message to the relay terminal to configure an indirect path to the remote terminal. Accordingly, the relay terminal can configure an indirect path with the indicated remote terminal and transmit the data of the remote terminal to the base station. Additionally, data of the remote terminal received from the base station can be transmitted to the remote terminal.

However, step S1010 can be performed only when adding an indirect path to the remote terminal. That is, when adding a direct path to the remote terminal in a situation where the remote terminal and the relay terminal configure an indirect path, step S1020 may be performed without step S1010. Therefore, step S1010 can be selectively performed only when necessary.

The base station may perform a step of transmitting configuration information for configuring multiple paths including a direct path and an indirect path to the remote terminal to the remote terminal (S1020).

For example, the base station may transmit configuration information for configuring multiple paths including a direct path to a remote terminal and an indirect path through a relay terminal. As an example, configuration information may be transmitted from the base station through higher layer signaling. For example, configuration information can be transmitted through RRC messages. As another example, configuration information may be transmitted to a remote terminal through a relay terminal.

Configuration information includes direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, and separate signaling. It may include at least one of radio bearer (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. For example, the configuration information may include additional direct path configuration information for additionally configuring a direct path to the remote terminal. Additionally, the configuration information may include indirect path additional configuration information for additionally configuring an indirect path to the remote terminal. Additionally, the configuration information may include direct path RLC bearer configuration information and/or indirect path RLC bearer configuration information for configuring a path for each bearer. Alternatively, the configuration information may include bearer mapping configuration information for mapping bearers and paths. In addition, the configuration information may include at least one radio bearer configuration information among direct path radio bearer configuration information, indirect path radio bearer configuration information, split SRB configuration information, and split DRB configuration information. The configuration information may include L2 relay terminal identification information connected to the remote terminal.

For example, when a remote terminal receives configuration information from a base station, it can configure multiple paths to the terminal based on the configuration information. As an example, the remote terminal may configure the primary path of the split signaling radio bearer (Split SRB) as a direct path. As another example, the remote terminal may configure an indirect path by establishing a PC5 RRC connection with the relay terminal.

The remote terminal can be configured by adding a direct path and/or an indirect path using information included in the configuration information. Alternatively, the remote terminal may configure a radio bearer indicated by configuration information in the terminal and control communication to be performed using a direct path and/or an indirect path.

The base station can communicate with a remote terminal through multiple configured paths. However, limitations in communication may occur due to various factors during communication. For example, a communication failure situation may occur, such as a wireless link failure. The remote terminal can monitor whether the wireless link has failed.

When a wireless link failure is detected in at least one of the plurality of paths in the remote terminal, the base station may perform a step of receiving an RRC message (S1030).

For example, the remote terminal can monitor whether a wireless link failure occurs for multiple paths. If a wireless link failure is detected in one or more of the plurality of paths, the base station can receive information about the occurrence of the failure through an RRC message.

For example, if the path on which a wireless link failure is detected is a direct path, the RRC message may be received as path failure reporting through an indirect path.

As another example, if the path where the wireless link failure was detected is an indirect path, the RRC message may be received as path failure reporting through a direct path.

For example, a wireless link failure detected on the indirect path may be a notification due to a sidelink failure or a wireless link failure between the relay terminal and the base station on the indirect path. That is, when a sidelink failure is detected, a problem may occur in communication between the remote terminal and the relay terminal, and a wireless link failure may be detected on the indirect path. Alternatively, if a wireless link failure occurs between the relay terminal and the base station, the remote terminal can detect the wireless link failure on the indirect path. In this case, a wireless link failure between the relay terminal and the base station may be notified.

As another example, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal may perform a cell selection or relay selection operation according to the RRC reset procedure. Additionally, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal can transmit an RRC reset request message to the base station. Accordingly, the base station can receive an RRC reset request message. The cell selection or relay selection operation by the remote terminal may be performed before receiving the RRC reset request message or after receiving the RRC reset request message. Alternatively, reception of the RRC reset request message may be performed as one of the cell selection or relay selection operation processes.

Meanwhile, the RRC message transmitted for path failure reporting may include information on the cause of failure. Alternatively, the RRC message may include information about the radio bearer for which a radio link failure was detected, failure type information, etc.

Through the above operation, a remote terminal that communicates through a plurality of different paths such as direct path and indirect path can prevent deterioration of the communication situation by taking quick action when a wireless link failure is detected.

Hereinafter, various functions and embodiments that the above-described remote terminal, relay terminal, and base station can perform will be described in more detail. Each function and embodiment described below can be performed by a remote terminal, relay terminal, and base station in any combination.

For convenience of explanation, the L2 U2N remote terminal is referred to as a remote terminal below. This is for convenience of explanation, and any terminal connected to the network through any relay terminal/node, such as an L3 U2N remote terminal, IAB, or mobile-IAB, may also be included in the remote terminal. The interface between the remote terminal and the relay terminal may be connected through PC5, F1, or any non-3gpp technology.

Add/edit/remove remote terminal path

The remote terminal in the RRC idle/inactive state uses an indirect path through the relay terminal (SRB/DRB configuration to transmit and receive RRC messages and/or user plane data through an indirect path, or terminal connection configuration procedure for the remote terminal). can be set. Afterwards, the base station serving the terminal can add a route directly to the terminal.

As an example, the remote terminal and relay terminal can perform a sidelink discovery procedure and establish a PC5-RRC connection. The remote terminal may transmit an RRC message (e.g. RRC setup request) to the base station to establish a connection with the base station through the relay terminal. If the relay terminal is not in the RRC connection state, the relay terminal that receives the message on the corresponding PC5 relay RLC channel can perform (RRC) connection setup. During RRC connection establishment of the relay terminal, the base station may configure SRB0 to relay the Uu relay RLC channel to the relay terminal. The base station can respond to the remote terminal with an RRC Setup message. The RRC setup message can be transmitted to the remote terminal using the SRB0 relaying channel through Uu and the corresponding PC5 relay RLC channel through PC5. The base station and relay terminal can perform a relaying channel setup procedure through Uu. The relay/remote terminal can set the PC5 relay RLC channel for SRB1 relaying. The remote terminal transmits an RRC setup completion message through the relay terminal. The remote terminal and base station set security. The base station may transmit an RRC reconfiguration message to the remote terminal through the relay terminal to set up SRB2/DRBs for relay purposes. The RRC reconfiguration message may include configuration information for adding/editing/removing the path of the remote terminal. For example, configuration information includes measurement configuration, reporting configuration, cell group configuration information (CellGroupConfig) for the direct path of the remote terminal, RLC bearer configuration information for the direct path, SRB0/SRB1/SRB2/DRBs configuration through the direct path, (sidelink) SRB0/SRB1/SRB2/DRBs configuration through indirect path of remote terminal, SRAP configuration for sidelink L2 remote terminal, PC5 (relay) RLC channel configuration information between relay terminal and remote terminal, and indirect path and direct path It may include one or more of the split SRB1/SRB2/DRBs configurations that all use.

The remote terminal can set the route directly. Afterwards, the base station serving the terminal can add an indirect path through the relay terminal. As an example, the remote terminal may perform an RRC setup procedure with the base station. The base station can send an RRC reconfiguration message to the (remote) terminal through the Uu interface to add SRBs/DRBs for relay purposes. The RRC reconfiguration message may include configuration information for adding/editing/removing the path of the remote terminal. For example, configuration information includes measurement configuration, reporting configuration, cell group configuration information (CellGroupConfig) for the direct path of the remote terminal, RLC bearer configuration information for the direct path, SRB0/SRB1/SRB2/DRBs configuration through the direct path, (Sidelink) SRB0/SRB1/SRB2/DRBs configuration through indirect path of remote terminal, SRAP configuration for sidelink L2 remote terminal, PC5 (relay) RLC channel configuration information between relay terminal and remote terminal, indirect path and direct path Split SRB1/SRB2/DRBs configuration using all, source/destination L2 ID for relay terminal or remote terminal, relay terminal ID, local ID of remote terminal, L2 ID, C-RNTI, Uu for relaying And it may include one or more of the PC5 relay RLC channel configuration and bearer mapping configuration. To add/edit/release an indirect path, the remote terminal and relay terminal can perform a sidelink discovery procedure. The remote terminal can establish a PC5-RRC connection with the relay terminal. The remote terminal or relay terminal can indicate the corresponding PC5-RRC connection information to the base station.

Before, simultaneously with, or after the base station transmits the RRC reconfiguration message to the remote terminal through the Uu interface on the direct path, the base station may transmit the RRC reconfiguration message to the relay terminal. The RRC reconfiguration message contains the source/destination L2 ID for the relay terminal or remote terminal, relay terminal ID, local ID of the remote terminal, L2 ID, C-RNTI, Uu for relaying, and PC5 relay RLC channel configuration and bearer mapping. It may contain one or more of the configurations. Alternatively, the RRC reconfiguration message transmitted by the base station to the remote terminal through the Uu interface on the direct path may include a container/IE/command for configuring the relay terminal. The remote terminal can transmit the corresponding container/IE/command to the relay terminal. The configuration can be applied to the relay terminal and an RRC reconfiguration complete message for this can be transmitted to the base station. Alternatively, the base station may transmit an RRC reconfiguration message to the remote terminal through an indirect path. The RRC reconfiguration message may be included through container/IE/command in the RRC reconfiguration message for configuring the relay terminal. The base station and relay terminal can perform a relaying channel setup procedure through Uu. Depending on the configuration received from the base station, the relay terminal and remote terminal can set the PC5 relay RLC channel for SRB/DRB relaying. The remote terminal may transmit an RRC reconfiguration complete message through a direct path.

When a remote terminal sets/configures/modifies a direct path and an indirect path in the terminal by adding/editing a route (for example, setting/configuring RRC/SRBs/DRBs in the terminal through multiple paths including direct paths and indirect paths) /modify), one of multiple (or two) paths may be indicated/configured/set/considered as the primary path. For convenience of explanation, the path used for default/priority transmission/reception of one or more of the RRC message, PDCP control PDU, and PDCP data PDU (e.g. user data) in a terminal configured with both a direct path and an indirect path is referred to as the primary path. It is written as This is for convenience of explanation and may be replaced with any other name.

As an example, the first/first path on which the remote terminal establishes an RRC connection among a plurality of paths may be considered the primary path for the remote terminal. The base station can configure a secondary path through the primary path for the remote terminal. As another example, the primary path may be selected from a direct path or an indirect path. As another example, the primary path may be selected among the RLC entity and the SRAP/PC5-RLC entity for uplink data transmission. As another example, the primary path may be configured to indicate the primary RLC entity/PC5-RLC entity for transmitting the PDCP control PDU. The corresponding RLC entity/PC5-RLC entity can be distinguished through PCell LCID/SL-LCID. As another example, the PDCP control PDU can be transmitted through the primary path. As another example, the primary path may be indicated/configured with information that is distinct from information for indicating the primary RLC entity/PC5-RLC entity for transmitting the PDCP control PDU. For example, a PCDP PDCP control PDU may be transmitted through a path other than the primary path.

As another example, the PCell of the remote terminal may be a cell serving the primary path. For example, if the direct path of the remote terminal is the primary path, the PCell serving the remote terminal becomes the PCell of the remote terminal. If the remote terminal's indirect path is the primary path, the PCell serving the relay terminal can be the remote terminal's PCell.

As another example, the base station may configure information to indicate a primary path to the remote terminal through an RRC reconfiguration message.

As another example, the primary path may be the default path along which any/most RRC messages are transmitted. As another example, RRC messages provided through a path other than the primary path (e.g. secondary path) may be limited to specific RRC messages. For example, when RLF is declared/detected on the primary path, a message to notify/instruct the corresponding information (e.g. failure information) may be transmitted to the base station through the secondary path. Alternatively, arbitrary terminal help information helpful in determining the corresponding path may be transmitted to the base station through a secondary path.

As another example, when multiple paths are configured in the terminal, radio bearer/SRB/DRB through direct path, radio bearer/SRB/DRB through indirect path, and split radio bearer/using both direct and indirect paths. One or more of SRB/DRB may be configured.

As another example, if a wireless link failure is detected on the primary path, the remote terminal can trigger RRC reset on the primary path. As another example, when a wireless link failure is detected on the primary path, if the remote terminal is capable of transmitting and receiving data through the secondary path, it can switch and transmit and receive data through the secondary path. For this, a conditional path change configuration can be configured in the terminal. The configuration can be configured through candidate path configuration and execution conditions. The corresponding path configuration may include one or more of the configuration information described in this specification.

As another example, the remote terminal may trigger RRC reset only on the primary path. As another example, the remote terminal may perform cell selection or relay selection among the primary path and secondary path. As another example, a (priority) path through which the remote terminal will trigger RRC reset may be configured in the terminal by the base station.

FIG. 11 is a diagram to explain an example of a split radio bearer/SRB/DRB configuration through multiple paths.

Referring to FIG. 11, the remote terminal may be connected to the base station via a relay terminal through an indirect path. Alternatively, the remote terminal may be directly connected to the base station through a direct path. When a remote terminal is connected to a base station through a direct path, PDCP, RLC, and MAC entities within the remote terminal and the base station are configured to transmit and receive data. When the remote terminal is connected to the base station through an indirect path, PC5-MAC, PC5-RLC, and SRAP of the remote terminal and relay terminal are configured. The relay terminal is connected to the base station through MAC, RLC, and SRAP entities.

Handling wireless link failure of multi-path configuration terminal

The remote terminal can perform wireless link monitoring only on the primary path. Alternatively, the remote terminal can perform wireless link monitoring on both the primary path and the secondary path.

As an example, when the remote terminal establishes the first RRC connection through a relay terminal and is connected to the base station (or when the remote terminal is connected to the base station using an indirect path as the primary path), the remote terminal establishes a wireless link (wireless link) between the terminal and the base station. You can suspend Radio Link Monitoring (RLM) on Uu) (or on the direct path).

As another example, when the remote terminal establishes the first RRC connection through the relay terminal and is connected to the base station (or when the remote terminal is connected to the base station using the indirect path as the primary path), the remote terminal establishes a wireless link (wireless link) between the terminal and the base station. RLM can be performed on Uu) (or on the direct path).

As another example, when the remote terminal is connected to the base station by establishing the first RRC connection through the relay terminal (or when the remote terminal is connected to the base station using the indirect path as the primary path), the remote terminal transmits uplink data through a direct path. If instructed to transmit via, the remote terminal can perform RLM on the radio link (Uu) between the terminal and the base station (or on the direct path).

As another example, when the remote terminal establishes the first RRC connection through the relay terminal and connects to the base station (or when the remote terminal connects to the base station using the indirect path as the primary path), the remote terminal detects a sidelink wireless link failure. If, or in the RRC connected state, the remote terminal receives a sidelink notification message according to a specific operation of the relay terminal, or in the RRC connected state, if the remote terminal receives the PC5 unicast link release indicated by the upper layer, the remote terminal Can perform/resume RLM on the radio link (Uu) between the terminal and the base station (or on the direct path).

As another example, when the remote terminal is connected to the base station through a secondary path through a relay terminal (or when the remote terminal is connected to the base station using an indirect path as a secondary path), the remote terminal is connected to the wireless link (Uu) between the terminal and the base station. RLM can be performed.

As another example, when the remote terminal is connected to the base station by establishing the first RRC connection through the relay terminal (or when the remote terminal is connected to the base station using the indirect path as the primary path), in the RRC connection state, the remote terminal uses the sidelink wireless Link failure (e.g. upon indication from sidelink RLC entity that the maximum number of retransmissions for a specific destination has been reached; or upon T400(Upon transmission of RRCReconfigurationSidelink) expiry for a specific destination; or upon indication from MAC entity that the maximum number of If consecutive HARQ DTX for a specific destination has been reached; or upon integrity check failure indication from sidelink PDCP entity concerning SL-SRB2 or SL-SRB3 for a specific destination) is detected, or in the RRC connection state, the remote terminal Action (e.g. upon Uu RLF; upon reception of an RRCReconfiguration including the reconfigurationWithSync; upon cell reselection; Upon receiving a sidelink notification message (upon L2 U2N Relay UE's RRC connection failure including RRC connection reject and T300 expiry and RRC resume failure), the remote terminal indirectly connects to SRBs and DRBs (all except SRB0/broadcast-MRB). Transmissions over a path can be suspended. If it is determined that the connection between the relay terminal and PC5-RRC will be disconnected, the remote terminal can perform PC5-RRC disconnection. The remote terminal can release the sidelink radio bearer between relay terminals. And/or the remote terminal may release the L2 entity through an indirect path for the split bearer. Alternatively, when the remote terminal receives PC5 unicast link release indicated by the upper layer in the RRC connection state, if it is determined that the relay terminal and PC5-RRC connection are released, the remote terminal can perform PC5-RRC disconnection. there is. The remote terminal can perform either cell selection according to the cell selection process or relay selection according to the relay selection procedure. The remote terminal may initiate transmission of an RRC reset request message. For example, the remote terminal may transmit an RRC reset request message through the selected cell. Alternatively, the remote terminal may transmit an RRC reset request message to the base station through the selected relay.

As another example, when the remote terminal is connected to the base station by establishing the first RRC connection through the relay terminal (or when the remote terminal is connected to the base station using the indirect path as the primary path), in the RRC connection state, the remote terminal uses the sidelink wireless When a link failure is detected, or in the RRC connected state, the remote terminal receives a sidelink notification message according to a specific operation of the relay terminal, or in the RRC connected state, the remote terminal receives the PC5 unicast link release indicated by the upper layer. Then, the remote terminal can suspend transmission through the indirect path for SRBs and DRBs (all except SRB0/broadcast-MRB). If it is determined that the connection between the relay terminal and PC5-RRC will be disconnected, the remote terminal can perform PC5-RRC disconnection. The remote terminal can release the sidelink radio bearer between relay terminals. And/or the remote terminal may release the L2 entity through an indirect path for the split bearer. (If the direct path is maintained or if the direct path satisfies specific conditions (e.g. threshold, timing advance timer, or specific timer operation), the remote terminal reports sidelink wireless link failure and sidelink notification through the direct path. Information to indicate one or more of message reception and PC5-RRC disconnection (or the corresponding cause) may be transmitted to the base station. The remote terminal can maintain a wireless connection with the corresponding cell if the direct path is maintained or if the direct path satisfies specific conditions indicated (e.g. threshold, timing advance timer, or specific timer operation). The remote terminal can maintain data communication through the corresponding cell. The base station can set/modify/reconfigure radio bearer/SRB/DRB through direct path through RRC reconfiguration message. The base station can release/modify/reconfigure the radio bearer/SRB/DRB and/or split radio bearer/SRB/DRB through the indirect path through the RRC reconfiguration message (e.g. split radio bearer/SRB/DRB through the direct path). Reconfiguration with radio bearer/SRB/DRB).

As another example, when a remote terminal establishes an initial RRC connection through a relay terminal and is connected to the base station (or when a remote terminal connects to the base station using an indirect path as the primary path), in the RRC connection state, the remote terminal uses a sidelink wireless link. When a failure is detected, or in an RRC connection state, when the remote terminal receives a sidelink notification message according to a specific operation of the relay terminal, or in an RRC connection state, when the remote terminal receives a PC5 unicast link release indicated by the upper layer , the remote terminal can suspend transmission through the indirect path for SRBs and DRBs (all except SRB0/broadcast-MRB). Alternatively, the remote terminal can suspend SRBs and DRBs (all through indirect paths except SRB0/broadcast-MRB). If it is determined that the connection between the relay terminal and PC5-RRC will be disconnected, the remote terminal can perform PC5-RRC disconnection. (simultaneously with, after, or before the RLF on the primary path) If the remote terminal detects a radio link failure on the direct path, the remote terminal directly connects to SRBs and DRBs (all except SRB0/broadcast-MRB) Transmissions via path/indirect path can be suspended. Alternatively, the remote terminal can suspend SRBs and DRBs (all except SRB0/broadcast-MRB).

The remote terminal can perform either cell selection according to the cell selection process or relay selection according to the relay selection procedure. The remote terminal may initiate transmission of an RRC reset request message. For example, the remote terminal can transmit an RRC reset request message through the selected cell. Alternatively, the remote terminal may transmit an RRC reset request message to the base station through the selected relay.

As another example, when the remote terminal is connected to the base station by establishing the first RRC connection through a direct path (or when the remote terminal is connected to the base station with the direct path as the primary path), in the RRC connection state, the remote terminal connects to the direct path ( e.g. upon detecting a wireless link failure on Uu), the remote terminal can suspend transmission through the direct path to SRBs and DRBs (all except SRB0/broadcast-MRB). Alternatively, the remote terminal can suspend SRBs and DRBs (all except SRB0/broadcast-MRB). The remote terminal can perform cell selection according to the cell selection process. The remote terminal may initiate transmission of an RRC reset request message. For example, the remote terminal can transmit an RRC reset request message through the selected cell.

As another example, when the remote terminal establishes an initial RRC connection through a direct path and connects to the base station (or, when the remote terminal connects to the base station with the direct path as the primary path), in the RRC connection state, the remote terminal connects to the direct path (e.g. Upon detecting a radio link failure on Uu), the remote terminal can suspend transmission through the direct path to SRBs and DRBs (all except SRB0/broadcast-MRB). In the RRC connection state, the remote terminal does not detect a sidelink wireless link failure, or in the RRC connection state, if the remote terminal does not receive a sidelink notification message according to a specific operation of the relay terminal, or in the RRC connection state, the remote terminal If the PC5 unicast link release indicated by the layer is not received, the remote terminal can maintain transmission through the indirect path to SRBs and DRBs. If it is determined that the connection between the relay terminal and PC5-RRC will be disconnected, the remote terminal can perform PC5-RRC disconnection. The remote terminal can release the sidelink radio bearer between relay terminals. And/or the remote terminal can suspend SRBs and DRBs (all except SRB0/broadcast-MRB). The remote terminal can release the L2 entity through the indirect path for the split bearer. Otherwise, the remote terminal can maintain the PC5 RRC connection.

(The remote terminal detects a direct path wireless link failure through the indirect path if the indirect path is maintained or if the indirect path satisfies the specified specific conditions (e.g. SD-RSRP/SL-RSRP threshold, specific timer operation). Information for instructions can be transmitted to the base station. The remote terminal can maintain a wireless connection through the path if the indirect path is maintained or if the indirect path satisfies specific specified conditions (e.g. threshold, specific timer operation). Data communication can be maintained through that path. The base station can set/modify/reconfigure the radio bearer/SRB/DRB through the indirect path through the RRC reconfiguration message. The base station can release/modify/reconfigure the radio bearer/SRB/DRB and/or split radio bearer/SRB/DRB through the direct path through the RRC reconfiguration message (e.g. split radio bearer/SRB/DRB through the indirect path). Reconfiguration with radio bearer/SRB/DRB).

As another example, when the remote terminal establishes an initial RRC connection through a direct path and connects to the base station (or, when the remote terminal connects to the base station with the direct path as the primary path), in the RRC connection state, the remote terminal connects to the direct path (e.g. Upon detecting a radio link failure on Uu), the remote terminal can suspend transmission through the direct path to SRBs and DRBs (all except SRB0/broadcast-MRB). In the RRC connection state, the remote terminal detects a sidelink wireless link failure, or in the RRC connection state, when the remote terminal receives a sidelink notification message according to a specific operation of the relay terminal, or in the RRC connection state, the remote terminal sends a message to the upper layer. Upon receiving the PC5 unicast link release indicated by , the remote terminal can suspend transmission through the indirect path for SRBs and DRBs (all except SRB0/broadcast-MRB). Alternatively, the remote terminal can suspend SRBs and DRBs (via all indirect paths except SRB0/broadcast-MRB). Alternatively, the remote terminal can suspend transmission through the direct path/indirect path for SRBs and DRBs. Alternatively, the remote terminal can suspend SRBs and DRBs (all except SRB0/broadcast-MRB).

The remote terminal can perform either cell selection according to the cell selection process or relay selection according to the relay selection procedure. The remote terminal may initiate transmission of an RRC reset request message. For example, the remote terminal can transmit an RRC reset request message through the selected cell. Alternatively, the remote terminal may transmit an RRC reset request message to the base station through the selected relay.

As another example, when the remote terminal is connected to the base station by establishing the first RRC connection through a direct path (or when the remote terminal is connected to the base station using the direct path as the primary path), in the RRC connection state, the remote terminal is connected to the sidelink wireless link. When a failure is detected, or in the RRC connection state, when the remote terminal receives a sidelink notification message according to a specific operation of the relay terminal, the remote terminal establishes an indirect path to SRBs and DRBs (all except SRB0/broadcast-MRB). You can suspend transmission through If it is determined that the connection between the relay terminal and PC5-RRC will be disconnected, the remote terminal can perform PC5-RRC disconnection. The remote terminal can release the sidelink radio bearer between relay terminals. And/or the remote terminal may release the L2 entity through an indirect path for the split bearer. Alternatively, when the remote terminal receives PC5 unicast link release indicated by the upper layer in the RRC connection state, if it is determined that the relay terminal and PC5-RRC connection are released, the remote terminal can perform PC5-RRC disconnection. there is. The remote terminal may transmit information to indicate one or more of sidelink wireless link failure, sidelink notification message reception, and PC5-RRC disconnection (or the corresponding cause) through a direct path to the base station. The remote terminal can maintain a wireless connection with the corresponding cell if the direct path is maintained or if the direct path satisfies specific conditions indicated (e.g. threshold, timing advance timer, or specific timer operation). The remote terminal can maintain data communication through the corresponding cell. The base station can set/modify/reconfigure radio bearer/SRB/DRB through direct path through RRC reconfiguration message. The base station can release/modify/reconfigure the radio bearer/SRB/DRB and/or split radio bearer/SRB/DRB through the indirect path through the RRC reconfiguration message (e.g. split radio bearer/SRB/DRB through the direct path). Reconfiguration with radio bearer/SRB/DRB).

As described above, according to the present disclosure, a remote terminal can stably transmit data through multiple paths and can effectively handle wireless link failure. Below, the configuration of the remote terminal and base station that can perform the operations and embodiments of the remote terminal, relay terminal, and base station described above will be described. Even if the description is omitted below for convenience of understanding, each entity may perform some or all of the above-described embodiments.

Figure 12 is a diagram showing the configuration of a remote terminal according to one embodiment.

Referring to FIG. 12, a remote terminal 1200 that performs communication through multiple paths includes a receiver 1230 that receives configuration information for configuring multiple paths including a direct path and an indirect path from a base station, and the configuration information. It may include a control unit that configures multiple paths and a transmitter 1220 that transmits an RRC message when a wireless link failure is detected in at least one of the multiple paths.

For example, the receiving unit 1230 may receive configuration information for configuring multiple paths including a direct path to the base station and an indirect path through a relay terminal. As an example, configuration information may be received from a base station through higher layer signaling. For example, configuration information may be received through an RRC message. As another example, configuration information may be received through a relay terminal.

For example, the configuration information includes direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, and indirect path radio bearer configuration. It may include at least one of information, split signaling radio bearer (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. For example, the configuration information may include additional direct path configuration information for additionally configuring a direct path to the remote terminal. Additionally, the configuration information may include indirect path additional configuration information for additionally configuring an indirect path to the remote terminal. Additionally, the configuration information may include direct path RLC bearer configuration information and/or indirect path RLC bearer configuration information for configuring a path for each bearer. Alternatively, the configuration information may include bearer mapping configuration information for mapping bearers and paths. In addition, the configuration information may include at least one radio bearer configuration information among direct path radio bearer configuration information, indirect path radio bearer configuration information, split SRB configuration information, and split DRB configuration information. The configuration information may include L2 relay terminal identification information connected to the remote terminal.

Meanwhile, when the control unit 1210 receives configuration information from the base station, it can configure multiple paths to the terminal based on the configuration information. As an example, the control unit 1210 may configure the primary path of the split signaling radio bearer (Split SRB) as a direct path. As another example, the control unit 1210 may configure an indirect path by establishing a PC5 RRC connection with the relay terminal.

The control unit 1210 can configure a direct path and/or an indirect path by adding the information included in the configuration information. Alternatively, the control unit 1210 may configure a radio bearer indicated by configuration information in the terminal and control communication to be performed using a direct path and/or an indirect path.

The control unit 1210 can communicate with the base station through multiple configured paths. However, limitations in communication may occur due to various factors during communication. For example, a communication failure situation may be detected, such as a wireless link failure.

For example, the control unit 1210 can monitor whether a wireless link failure occurs for multiple paths. If a wireless link failure is detected in one or more of the plurality of paths, the transmitter 1220 can transmit information about the occurrence of the failure through an RRC message.

For example, if the path on which a wireless link failure is detected is a direct path, the RRC message may be transmitted as path failure reporting through an indirect path.

As another example, if the path where a wireless link failure is detected is an indirect path, the RRC message may be transmitted as path failure reporting through a direct path.

For example, a wireless link failure detected on the indirect path may be a notification due to a sidelink failure or a wireless link failure between the relay terminal and the base station on the indirect path. That is, when a sidelink failure is detected, a problem may occur in communication between the remote terminal and the relay terminal, and a wireless link failure may be detected on the indirect path. Alternatively, if a wireless link failure occurs between the relay terminal and the base station, the control unit 1210 can detect the wireless link failure on the indirect path. In this case, a wireless link failure between the relay terminal and the base station may be notified.

As another example, when a radio link failure is detected in both the direct path and the indirect path, the control unit 1210 may perform a cell selection or relay selection operation according to an RRC reset procedure. Additionally, when a wireless link failure is detected in both the direct path and the indirect path, the transmitter 1220 may transmit an RRC reset request message to the base station. The cell selection or relay selection operation may be performed before transmitting the RRC reset request message, or may be performed after transmitting the RRC reset request message. Alternatively, transmission of the RRC reset request message may be performed as one of cell selection or relay selection operations.

Meanwhile, the RRC message transmitted for path failure reporting may include information on the cause of failure. Alternatively, the RRC message may include information about the radio bearer for which a radio link failure was detected, failure type information, etc.

In addition, the control unit 1210 controls the overall operation of the remote terminal 1200 according to the multi-path configuration and wireless link failure processing operations required to perform the present disclosure described above.

The transmitting unit 1220 and the receiving unit 1230 are used to transmit and receive signals, messages, and data necessary to perform the present disclosure described above with the base station and relay terminal.

Figure 13 is a diagram showing the configuration of a base station according to one embodiment.

Referring to FIG. 13, the base station 1300, which controls communication through multiple paths of the remote terminal, transmits an RRC reconfiguration message for indirect path configuration to the relay terminal providing connection to the remote terminal, and configures the direct path and indirect path. A transmitter 1320 that transmits configuration information for configuring multiple paths including paths to the remote terminal, and a receiver that receives an RRC message when a wireless link failure is detected in at least one of the multiple paths in the remote terminal. It may include (1330).

For example, the transmitter 1320 may transmit an RRC reconfiguration message to configure an indirect path to the remote terminal to the relay terminal. Accordingly, the relay terminal can configure an indirect path with the indicated remote terminal and transmit the data of the remote terminal to the base station. Additionally, the relay terminal may transmit the data of the remote terminal received from the base station to the remote terminal.

However, the above-described operation can be performed only when adding an indirect path to the remote terminal. That is, when adding a direct path to the remote terminal in a situation where the remote terminal and the relay terminal have configured an indirect path, transmission of the RRC reconfiguration message to the relay terminal may be omitted.

Meanwhile, the transmitter 1320 can transmit configuration information for configuring multiple paths including a direct path to a remote terminal and an indirect path through a relay terminal. As an example, configuration information may be transmitted from the base station through higher layer signaling. For example, configuration information can be transmitted through RRC messages. As another example, configuration information may be transmitted to a remote terminal through a relay terminal.

Configuration information includes direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, and separate signaling. It may include at least one of radio bearer (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. For example, the configuration information may include additional direct path configuration information for additionally configuring a direct path to the remote terminal. Additionally, the configuration information may include indirect path additional configuration information for additionally configuring an indirect path to the remote terminal. Additionally, the configuration information may include direct path RLC bearer configuration information and/or indirect path RLC bearer configuration information for configuring a path for each bearer. Alternatively, the configuration information may include bearer mapping configuration information for mapping bearers and paths. In addition, the configuration information may include at least one radio bearer configuration information among direct path radio bearer configuration information, indirect path radio bearer configuration information, split SRB configuration information, and split DRB configuration information. The configuration information may include L2 relay terminal identification information connected to the remote terminal.

For example, when a remote terminal receives configuration information from a base station, it can configure multiple paths to the terminal based on the configuration information. As an example, the remote terminal may configure the primary path of the split signaling radio bearer (Split SRB) as a direct path. As another example, the remote terminal may configure an indirect path by establishing a PC5 RRC connection with the relay terminal.

The remote terminal can be configured by adding a direct path and/or an indirect path using information included in the configuration information. Alternatively, the remote terminal may configure a radio bearer indicated by configuration information in the terminal and control communication to be performed using a direct path and/or an indirect path.

The control unit 1310 can communicate with a remote terminal through multiple configured paths. However, limitations in communication may occur due to various factors during communication. For example, a communication failure situation may occur, such as a wireless link failure. The remote terminal can monitor whether the wireless link has failed.

Meanwhile, the remote terminal can monitor whether a wireless link failure occurs for multiple paths. If a wireless link failure is detected in one or more of the plurality of paths, the receiver 1330 can receive information about the occurrence of the failure through an RRC message.

For example, if the path on which a wireless link failure is detected is a direct path, the RRC message may be received as path failure reporting through an indirect path.

As another example, if the path where the wireless link failure was detected is an indirect path, the RRC message may be received as path failure reporting through a direct path.

For example, a wireless link failure detected on the indirect path may be a notification due to a sidelink failure or a wireless link failure between the relay terminal and the base station on the indirect path. That is, when a sidelink failure is detected, a problem may occur in communication between the remote terminal and the relay terminal, and a wireless link failure may be detected on the indirect path. Alternatively, if a wireless link failure occurs between the relay terminal and the base station, the remote terminal can detect the wireless link failure on the indirect path. In this case, a wireless link failure between the relay terminal and the base station may be notified.

As another example, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal may perform a cell selection or relay selection operation according to the RRC reset procedure. Additionally, when a radio link failure is detected in both the direct path and the indirect path, the remote terminal can transmit an RRC reset request message to the base station. Accordingly, the receiving unit 1330 can receive the RRC reset request message. The cell selection or relay selection operation by the remote terminal may be performed before receiving the RRC reset request message or after receiving the RRC reset request message. Alternatively, reception of the RRC reset request message may be performed as one of the cell selection or relay selection operation processes.

Meanwhile, the RRC message transmitted for path failure reporting may include information on the cause of failure. Alternatively, the RRC message may include information about the radio bearer for which a radio link failure was detected, failure type information, etc.

In addition, the control unit 1310 controls the overall operation of the base station 1300 according to the multi-path configuration and wireless link failure processing operations required to perform the present disclosure described above.

The transmitting unit 1320 and the receiving unit 1330 are used to transmit and receive signals, messages, and data necessary to perform the present disclosure described above with a remote terminal and a relay terminal.

The above-described embodiments may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP, and 3GPP2. That is, steps, configurations, and parts that are not described in the present embodiments to clearly reveal the technical idea may be supported by the above-mentioned standard documents. Additionally, all terms disclosed in this specification can be explained by the standard documents disclosed above.

The above-described embodiments can be implemented through various means. For example, the present embodiments may be implemented by hardware, firmware, software, or a combination thereof.

In the case of hardware implementation, the method according to the present embodiments uses one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), and FPGAs. (Field Programmable Gate Arrays), processors, controllers, microcontrollers, or microprocessors.

In the case of implementation by firmware or software, the method according to the present embodiments may be implemented in the form of a device, procedure, or function that performs the functions or operations described above. Software code can be stored in a memory unit and run by a processor. The memory unit is located inside or outside the processor and can exchange data with the processor through various known means.

Additionally, terms such as "system", "processor", "controller", "component", "module", "interface", "model", or "unit" described above generally refer to computer-related entities hardware, hardware and software. It may refer to a combination of, software, or running software. By way of example, but not limited to, the foregoing components may be a process, processor, controller, control processor, object, thread of execution, program, and/or computer run by a processor. For example, both an application running on a controller or processor and the controller or processor can be a component. One or more components may reside within a process and/or thread of execution, and the components may be located on a single device (e.g., system, computing device, etc.) or distributed across two or more devices.

The above description is merely an illustrative explanation of the technical idea of the present disclosure, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present disclosure. In addition, the present embodiments are not intended to limit the technical idea of the present disclosure, but rather to explain it, so the scope of the present technical idea is not limited by these embodiments. The scope of protection of this disclosure should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this disclosure.

Claims (22)

In a method for a remote terminal to communicate through multiple paths,
Receiving configuration information for configuring multiple paths including a direct path and an indirect path from a base station;
configuring the plurality of paths by applying the configuration information; and
A method comprising transmitting an RRC message when a radio link failure is detected in at least one path among the plurality of paths. According to claim 1,
The configuration information is,
Direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, separate signaling radio bearer ( A method including at least one of split SRB (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. According to claim 1,
The step of configuring the multiple paths is,
The primary path of the split signaling radio bearer (Split SRB) is configured as the direct path,
How to set up a relay terminal and PC5 RRC connection. According to claim 1,
The RRC message is,
If the path on which the wireless link failure is detected is the direct path, path failure reporting is transmitted through the indirect path,
When the path on which the wireless link failure is detected is the indirect path, the path failure reporting is transmitted through the direct path. According to claim 4,
The wireless link failure detected on the indirect path,
A method of notification due to sidelink failure or wireless link failure between the relay terminal and the base station on the indirect path. According to claim 1,
The step of transmitting the RRC message is,
When a radio link failure is detected in both the direct path and the indirect path, a method of performing a cell selection or relay selection operation according to an RRC reset procedure and transmitting an RRC reset request message to the base station. In a method for a base station to control communication through multiple paths of a remote terminal,
Transmitting an RRC reconfiguration message for indirect path configuration to a relay terminal providing connection to the remote terminal;
Transmitting configuration information for configuring a plurality of paths including a direct path and the indirect path to the remote terminal to the remote terminal; and
A method comprising receiving an RRC message when a radio link failure is detected in at least one path among the plurality of paths in the remote terminal. According to claim 7,
The configuration information is,
Direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, separate signaling radio bearer ( A method including at least one of split SRB (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. According to claim 7,
The RRC message is,
If the path on which the wireless link failure is detected is the direct path, path failure reporting is received through the indirect path,
When the path on which the wireless link failure is detected is the indirect path, the path failure reporting is received through the direct path. According to clause 9,
The wireless link failure detected on the indirect path,
A method of notification due to sidelink failure or wireless link failure between the relay terminal and the base station on the indirect path. According to claim 7,
The RRC message is,
When a radio link failure is detected in both the direct path and the indirect path, the method is characterized in that it is an RRC reset request message according to an RRC reset procedure. In a remote terminal that performs communication through multiple paths,
A receiving unit that receives configuration information for configuring multiple paths including a direct path and an indirect path from a base station;
a control unit that configures the plurality of paths by applying the configuration information; and
A remote terminal including a transmitter that transmits an RRC message when a wireless link failure is detected in at least one path among the plurality of paths. According to claim 12,
The configuration information is,
Direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, separate signaling radio bearer ( A remote terminal that includes at least one of split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. According to claim 12,
The control unit,
A remote terminal that configures the primary path of the split signaling radio bearer (Split SRB) as the direct path and configures the multiple paths by establishing a PC5 RRC connection with the relay terminal. According to claim 12,
The RRC message is,
If the path on which the wireless link failure is detected is the direct path, path failure reporting is transmitted through the indirect path,
When the path on which the wireless link failure is detected is the indirect path, the remote terminal transmits the path failure reporting through the direct path. According to claim 15,
The wireless link failure detected on the indirect path,
A remote terminal that is notified due to sidelink failure or wireless link failure between the relay terminal and the base station on the indirect path. According to claim 12,
The control unit,
If a radio link failure is detected in both the direct path and the indirect path, perform a cell selection or relay selection operation according to the RRC reset procedure,
The transmitter is a remote terminal that transmits an RRC reset request message to the base station. In a base station that controls communication through multiple paths of a remote terminal,
Transmitting an RRC reconfiguration message for indirect path configuration to the relay terminal providing connection to the remote terminal,
A transmitter that transmits configuration information for configuring a plurality of paths including a direct path and the indirect path to the remote terminal to the remote terminal; and
A base station comprising a receiving unit that receives an RRC message when a wireless link failure is detected in at least one path among the plurality of paths in the remote terminal. According to claim 18,
The configuration information is,
Direct path additional configuration information, indirect path additional configuration information, direct path RLC bearer configuration information, indirect path RLC bearer configuration information, bearer mapping configuration information, direct path radio bearer configuration information, indirect path radio bearer configuration information, separate signaling radio bearer ( A base station that includes at least one of split SRB (split SRB) configuration information, split data radio bearer (split DRB) configuration information, and L2 relay terminal identification information. According to claim 18,
The RRC message is,
If the path on which the wireless link failure is detected is the direct path, path failure reporting is received through the indirect path,
When the path on which the wireless link failure is detected is the indirect path, the base station receives the path failure reporting through the direct path. According to claim 20,
The wireless link failure detected on the indirect path is,
A base station that is notified due to a sidelink failure or a wireless link failure between the base station and a relay terminal on the indirect path. According to claim 18,
The RRC message is,
When a radio link failure is detected in both the direct path and the indirect path, the base station is characterized in that it is an RRC reset request message according to an RRC reset procedure.

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